diff --git a/db/migrations/20260520211813_add_media_file_artists_composite_index.sql b/db/migrations/20260520211813_add_media_file_artists_composite_index.sql
new file mode 100644
index 000000000..f65050d80
--- /dev/null
+++ b/db/migrations/20260520211813_add_media_file_artists_composite_index.sql
@@ -0,0 +1,9 @@
+-- +goose Up
+CREATE INDEX IF NOT EXISTS media_file_artists_media_file_id_role
+    ON media_file_artists (media_file_id, role);
+DROP INDEX IF EXISTS media_file_artists_media_file_id;
+
+-- +goose Down
+CREATE INDEX IF NOT EXISTS media_file_artists_media_file_id
+    ON media_file_artists (media_file_id);
+DROP INDEX IF EXISTS media_file_artists_media_file_id_role;
diff --git a/persistence/criteria_sql.go b/persistence/criteria_sql.go
index a1bae3170..37e4ae340 100644
--- a/persistence/criteria_sql.go
+++ b/persistence/criteria_sql.go
@@ -3,7 +3,9 @@ package persistence
 import (
 	"errors"
 	"fmt"
+	"maps"
 	"reflect"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -147,7 +149,7 @@ func (c smartPlaylistCriteria) exprSQL(expr criteria.Expression) (squirrel.Sqliz
 			}
 			or = append(or, cond)
 		}
-		return or, nil
+		return mergeJsonConds(or), nil
 	case criteria.Is:
 		return mapExpr(e, func(fields map[string]any) squirrel.Sqlizer {
 			return squirrel.Eq(fields)
@@ -381,17 +383,173 @@ type roleCond struct {
 func (e roleCond) ToSql() (string, []any, error) {
 	var cond string
 	var args []any
-	var err error
 	if e.cond != nil {
-		cond, args, err = e.cond.ToSql()
-		cond = fmt.Sprintf("exists (select 1 from json_tree(media_file.participants, '$.%s') where key='name' and %s)", e.role, cond)
+		innerSQL, innerArgs, err := roleCondSQL(e.cond)
+		if err != nil {
+			return "", nil, err
+		}
+		cond = roleExistsSQL(innerSQL)
+		args = append([]any{e.role}, innerArgs...)
 	} else {
-		cond = fmt.Sprintf("exists (select 1 from json_tree(media_file.participants, '$.%s') where key='name')", e.role)
+		cond = "exists (select 1 from media_file_artists mfa where mfa.media_file_id = media_file.id and mfa.role = ?)"
+		args = []any{e.role}
 	}
 	if e.not {
 		cond = "not " + cond
 	}
-	return cond, args, err
+	return cond, args, nil
+}
+
+// roleCondSQL extracts SQL from a squirrel condition and rewrites the placeholder column name.
+func roleCondSQL(cond squirrel.Sqlizer) (string, []any, error) {
+	sql, args, err := cond.ToSql()
+	if err != nil {
+		return "", nil, err
+	}
+	return strings.ReplaceAll(sql, "value", "artist.name"), args, nil
+}
+
+// roleExistsSQL wraps a condition fragment in the standard role EXISTS subquery.
+func roleExistsSQL(innerCond string) string {
+	return fmt.Sprintf("exists (select 1 from media_file_artists mfa join artist on artist.id = mfa.artist_id "+
+		"where mfa.media_file_id = media_file.id and mfa.role = ? and %s)", innerCond)
+}
+
+// jsonCondBatchSize limits how many conditions are ORed inside a single EXISTS subquery
+// to stay within SQLite's expression tree depth limit (max 1000). The EXISTS wrapper
+// consumes ~4 levels; each ORed condition adds 1 level. Empirically, 496 is the maximum.
+const jsonCondBatchSize = 350
+
+// mergeJsonConds collapses multiple non-negated roleCond or tagCond entries for the same
+// field within an OR group into batched EXISTS subqueries with the conditions ORed inside.
+// This turns N separate correlated subqueries into ceil(N/batchSize), dramatically
+// improving performance for smart playlists with many patterns.
+func mergeJsonConds(or squirrel.Or) squirrel.Sqlizer {
+	type condEntry struct {
+		index int
+		cond  squirrel.Sqlizer
+	}
+	type group struct {
+		entries []condEntry
+		isRole  bool
+		numeric bool
+		tag     string
+	}
+	groups := make(map[string]*group)
+	for i, s := range or {
+		switch c := s.(type) {
+		case roleCond:
+			if c.not || c.cond == nil {
+				continue
+			}
+			g, exists := groups["role:"+c.role]
+			if !exists {
+				g = &group{isRole: true}
+				groups["role:"+c.role] = g
+			}
+			g.entries = append(g.entries, condEntry{index: i, cond: c.cond})
+		case tagCond:
+			if c.not || c.cond == nil {
+				continue
+			}
+			g, exists := groups["tag:"+c.tag]
+			if !exists {
+				g = &group{tag: c.tag, numeric: c.numeric}
+				groups["tag:"+c.tag] = g
+			}
+			g.entries = append(g.entries, condEntry{index: i, cond: c.cond})
+		}
+	}
+
+	merged := false
+	remove := make(map[int]bool)
+	var additions []squirrel.Sqlizer
+	for _, key := range slices.Sorted(maps.Keys(groups)) {
+		g := groups[key]
+		if len(g.entries) < 2 {
+			continue
+		}
+		merged = true
+		for _, e := range g.entries {
+			remove[e.index] = true
+		}
+		conds := make([]squirrel.Sqlizer, len(g.entries))
+		for i, e := range g.entries {
+			conds[i] = e.cond
+		}
+		if g.isRole {
+			role := key[len("role:"):]
+			for batch := range slices.Chunk(conds, jsonCondBatchSize) {
+				additions = append(additions, roleCondGroup{role: role, conds: batch})
+			}
+		} else {
+			for batch := range slices.Chunk(conds, jsonCondBatchSize) {
+				additions = append(additions, tagCondGroup{tag: g.tag, numeric: g.numeric, conds: batch})
+			}
+		}
+	}
+
+	if !merged {
+		return or
+	}
+
+	result := make(squirrel.Or, 0, len(or)-len(remove)+len(additions))
+	for i, s := range or {
+		if !remove[i] {
+			result = append(result, s)
+		}
+	}
+	result = append(result, additions...)
+	return result
+}
+
+// roleCondGroup represents multiple role conditions for the same role, merged into
+// a single EXISTS subquery for performance.
+type roleCondGroup struct {
+	role  string
+	conds []squirrel.Sqlizer
+}
+
+func (g roleCondGroup) ToSql() (string, []any, error) {
+	innerParts := make([]string, 0, len(g.conds))
+	allArgs := []any{g.role}
+	for _, c := range g.conds {
+		part, args, err := roleCondSQL(c)
+		if err != nil {
+			return "", nil, err
+		}
+		innerParts = append(innerParts, part)
+		allArgs = append(allArgs, args...)
+	}
+	cond := roleExistsSQL("(" + strings.Join(innerParts, " OR ") + ")")
+	return cond, allArgs, nil
+}
+
+// tagCondGroup represents multiple tag conditions for the same tag, merged into
+// a single EXISTS subquery for performance.
+type tagCondGroup struct {
+	tag     string
+	numeric bool
+	conds   []squirrel.Sqlizer
+}
+
+func (g tagCondGroup) ToSql() (string, []any, error) {
+	innerParts := make([]string, 0, len(g.conds))
+	var allArgs []any
+	for _, c := range g.conds {
+		part, args, err := c.ToSql()
+		if err != nil {
+			return "", nil, err
+		}
+		if g.numeric {
+			part = strings.ReplaceAll(part, "value", "CAST(value AS REAL)")
+		}
+		innerParts = append(innerParts, part)
+		allArgs = append(allArgs, args...)
+	}
+	cond := fmt.Sprintf("exists (select 1 from json_tree(media_file.tags, '$.%s') where key='value' and (%s))",
+		g.tag, strings.Join(innerParts, " OR "))
+	return cond, allArgs, nil
 }
 
 func singleField(values map[string]any) (string, any, criteria.FieldInfo, bool) {
diff --git a/persistence/criteria_sql_benchmark_test.go b/persistence/criteria_sql_benchmark_test.go
new file mode 100644
index 000000000..d901e9eda
--- /dev/null
+++ b/persistence/criteria_sql_benchmark_test.go
@@ -0,0 +1,236 @@
+package persistence
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/db"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/criteria"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/pocketbase/dbx"
+)
+
+const (
+	benchNumArtists      = 1_000
+	benchNumTracks       = 40_000
+	benchNumPatterns     = 500
+	benchArtistsPerTrack = 3
+)
+
+// BenchmarkSmartPlaylistRole compares role-based smart playlist query performance
+// between the current implementation (merged join-table via criteria pipeline) and
+// the old baseline (unmerged json_tree subqueries).
+func BenchmarkSmartPlaylistRole(b *testing.B) {
+	configtest.SetupConfig()
+	tmpDir := b.TempDir()
+	conf.Server.DbPath = filepath.Join(tmpDir, "bench-smartpl.db")
+	cleanup := db.Init(context.Background())
+	defer cleanup()
+	log.SetLevel(log.LevelFatal)
+
+	conn := dbx.NewFromDB(db.Db(), db.Dialect)
+	ctx := log.NewContext(context.Background())
+	user := model.User{ID: "bench-user", UserName: "bench", Name: "Bench User", IsAdmin: true}
+	ctx = request.WithUser(ctx, user)
+
+	setupBenchData(b, ctx, conn, user)
+	criteria.AddRoles([]string{"artist"})
+
+	// Build the criteria expression: 500 "contains artist" patterns in an OR group
+	anyExprs := make(criteria.Any, benchNumPatterns)
+	for i := range benchNumPatterns {
+		anyExprs[i] = criteria.Contains{"artist": fmt.Sprintf("Artist %04d", i)}
+	}
+	expr := criteria.Criteria{Expression: anyExprs, Sort: "title", Limit: 500}
+
+	b.Run("Current", func(b *testing.B) {
+		benchmarkCriteriaPipeline(b, ctx, expr)
+	})
+	b.Run("Baseline_UnmergedJSONTree", func(b *testing.B) {
+		benchmarkUnmergedJSONTree(b, ctx)
+	})
+}
+
+// benchmarkCriteriaPipeline runs the criteria through the actual production code path:
+// newSmartPlaylistCriteria → Where() → ToSql(), then executes the resulting query.
+func benchmarkCriteriaPipeline(b *testing.B, ctx context.Context, expr criteria.Criteria) {
+	b.Helper()
+
+	cSQL := newSmartPlaylistCriteria(expr)
+
+	// Build the full query matching buildSmartPlaylistQuery + addCriteria
+	sq := squirrel.Select("media_file.id").From("media_file")
+	cond, err := cSQL.Where()
+	if err != nil {
+		b.Fatal(err)
+	}
+	sq = sq.Where(cond)
+	if expr.Limit > 0 {
+		sq = sq.Limit(uint64(expr.Limit))
+	}
+	if order := cSQL.OrderBy(); order != "" {
+		sq = sq.OrderBy(order)
+	}
+
+	query, args, err := sq.PlaceholderFormat(squirrel.Question).ToSql()
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	runBenchQuery(b, ctx, query, args)
+}
+
+// benchmarkUnmergedJSONTree builds the old-style query with N separate json_tree EXISTS
+// subqueries (the pre-optimization baseline).
+func benchmarkUnmergedJSONTree(b *testing.B, ctx context.Context) {
+	b.Helper()
+
+	var sb strings.Builder
+	sb.WriteString("SELECT media_file.id FROM media_file WHERE (")
+	args := make([]any, 0, benchNumPatterns)
+	for i := range benchNumPatterns {
+		if i > 0 {
+			sb.WriteString(" OR ")
+		}
+		sb.WriteString("exists (select 1 from json_tree(media_file.participants, '$.artist') where key='name' and value LIKE ?)")
+		args = append(args, fmt.Sprintf("%%Artist %04d%%", i))
+	}
+	sb.WriteString(") ORDER BY media_file.title LIMIT 500")
+
+	runBenchQuery(b, ctx, sb.String(), args)
+}
+
+func runBenchQuery(b *testing.B, ctx context.Context, query string, args []any) {
+	b.Helper()
+	sqlDB := db.Db()
+	b.ResetTimer()
+	for range b.N {
+		rows, err := sqlDB.QueryContext(ctx, query, args...)
+		if err != nil {
+			b.Fatal(err)
+		}
+		for rows.Next() {
+			var id string
+			_ = rows.Scan(&id)
+		}
+		rows.Close()
+		if err := rows.Err(); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func setupBenchData(b *testing.B, ctx context.Context, conn *dbx.DB, user model.User) {
+	b.Helper()
+
+	sqlDB := db.Db()
+
+	ur := NewUserRepository(ctx, conn)
+	if err := ur.Put(&user); err != nil {
+		b.Fatal(err)
+	}
+	if err := ur.SetUserLibraries(user.ID, []int{1}); err != nil {
+		b.Fatal(err)
+	}
+
+	tx, err := sqlDB.Begin()
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	// Create artists
+	artistStmt, err := tx.Prepare("INSERT INTO artist (id, name) VALUES (?, ?)")
+	if err != nil {
+		b.Fatal(err)
+	}
+	for i := range benchNumArtists {
+		if _, err := artistStmt.Exec(fmt.Sprintf("artist-%04d", i), fmt.Sprintf("Artist %04d", i)); err != nil {
+			b.Fatal(err)
+		}
+	}
+	artistStmt.Close()
+
+	// Ensure folder exists
+	folderID := "bench-folder"
+	if _, err := tx.Exec("INSERT OR IGNORE INTO folder (id, library_id, path, name, parent_id) VALUES (?, 1, '.', '.', '')", folderID); err != nil {
+		b.Fatal(err)
+	}
+
+	// Create media files with participants JSON, cycling through artists
+	mfStmt, err := tx.Prepare(`INSERT INTO media_file (id, path, title, album, artist, artist_id, album_id,
+		duration, year, size, suffix, tags, participants, lyrics, library_id, folder_id, pid, codec)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`)
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	// Populate media_file_artists join table
+	mfaStmt, err := tx.Prepare("INSERT INTO media_file_artists (media_file_id, artist_id, role, sub_role) VALUES (?, ?, ?, ?)")
+	if err != nil {
+		b.Fatal(err)
+	}
+
+	for i := range benchNumTracks {
+		trackID := fmt.Sprintf("track-%05d", i)
+
+		// Assign benchArtistsPerTrack artists to each track, cycling through the pool
+		artistEntries := make([]map[string]string, benchArtistsPerTrack)
+		for a := range benchArtistsPerTrack {
+			artistIdx := (i + a) % benchNumArtists
+			artistEntries[a] = map[string]string{
+				"id":   fmt.Sprintf("artist-%04d", artistIdx),
+				"name": fmt.Sprintf("Artist %04d", artistIdx),
+			}
+		}
+		primaryArtistIdx := i % benchNumArtists
+		primaryArtistID := fmt.Sprintf("artist-%04d", primaryArtistIdx)
+		primaryArtistName := fmt.Sprintf("Artist %04d", primaryArtistIdx)
+
+		participants := map[string][]map[string]string{"artist": artistEntries}
+		participantsJSON, _ := json.Marshal(participants)
+
+		if _, err := mfStmt.Exec(
+			trackID,
+			fmt.Sprintf("music/%s.mp3", trackID),
+			fmt.Sprintf("Track %05d", i),
+			"Bench Album",
+			primaryArtistName,
+			primaryArtistID,
+			"bench-album",
+			180, 2024, 5000000, "mp3",
+			"{}",
+			string(participantsJSON),
+			"[]",
+			1, folderID, trackID, "mp3",
+		); err != nil {
+			b.Fatal(err)
+		}
+
+		// Insert all artist associations into the join table
+		for a := range benchArtistsPerTrack {
+			artistIdx := (i + a) % benchNumArtists
+			artistID := fmt.Sprintf("artist-%04d", artistIdx)
+			if _, err := mfaStmt.Exec(trackID, artistID, "artist", ""); err != nil {
+				b.Fatal(err)
+			}
+		}
+	}
+	mfStmt.Close()
+	mfaStmt.Close()
+
+	if err := tx.Commit(); err != nil {
+		b.Fatal(err)
+	}
+
+	b.Logf("Setup complete: %d artists, %d tracks (%d artists/track), %d patterns",
+		benchNumArtists, benchNumTracks, benchArtistsPerTrack, benchNumPatterns)
+}
diff --git a/persistence/criteria_sql_test.go b/persistence/criteria_sql_test.go
index ae2695a4d..5c8909e1c 100644
--- a/persistence/criteria_sql_test.go
+++ b/persistence/criteria_sql_test.go
@@ -1,6 +1,8 @@
 package persistence
 
 import (
+	"fmt"
+	"strings"
 	"time"
 
 	"github.com/navidrome/navidrome/model"
@@ -56,9 +58,9 @@ var _ = Describe("Smart playlist criteria SQL", func() {
 		Entry("numeric tag", criteria.Lt{"rate": 6}, "exists (select 1 from json_tree(media_file.tags, '$.rate') where key='value' and CAST(value AS REAL) < ?)", 6),
 		Entry("tag alias", criteria.Is{"albumtype": "album"}, "exists (select 1 from json_tree(media_file.tags, '$.releasetype') where key='value' and value = ?)", "album"),
 		Entry("field alias via tag registration", criteria.Is{"recordingdate": "2024-01-01"}, "media_file.date = ?", "2024-01-01"),
-		Entry("role is", criteria.Is{"artist": "u2"}, "exists (select 1 from json_tree(media_file.participants, '$.artist') where key='name' and value = ?)", "u2"),
-		Entry("role contains", criteria.Contains{"composer": "Lennon"}, "exists (select 1 from json_tree(media_file.participants, '$.composer') where key='name' and value LIKE ?)", "%Lennon%"),
-		Entry("role not contains", criteria.NotContains{"artist": "u2"}, "not exists (select 1 from json_tree(media_file.participants, '$.artist') where key='name' and value LIKE ?)", "%u2%"),
+		Entry("role is", criteria.Is{"artist": "u2"}, "exists (select 1 from media_file_artists mfa join artist on artist.id = mfa.artist_id where mfa.media_file_id = media_file.id and mfa.role = ? and artist.name = ?)", "artist", "u2"),
+		Entry("role contains", criteria.Contains{"composer": "Lennon"}, "exists (select 1 from media_file_artists mfa join artist on artist.id = mfa.artist_id where mfa.media_file_id = media_file.id and mfa.role = ? and artist.name LIKE ?)", "composer", "%Lennon%"),
+		Entry("role not contains", criteria.NotContains{"artist": "u2"}, "not exists (select 1 from media_file_artists mfa join artist on artist.id = mfa.artist_id where mfa.media_file_id = media_file.id and mfa.role = ? and artist.name LIKE ?)", "artist", "%u2%"),
 		// ReplayGain fields
 		Entry("rgAlbumGain is", criteria.Is{"rgAlbumGain": 0}, "media_file.rg_album_gain = ?", 0),
 		Entry("rgAlbumGain gt", criteria.Gt{"rgAlbumGain": -6.0}, "media_file.rg_album_gain > ?", -6.0),
@@ -70,9 +72,9 @@ var _ = Describe("Smart playlist criteria SQL", func() {
 			"exists (select 1 from json_tree(media_file.tags, '$.genre') where key='value')"),
 		// isMissing — roles
 		Entry("isMissing role [true]", criteria.IsMissing{"artist": true},
-			"not exists (select 1 from json_tree(media_file.participants, '$.artist') where key='name')"),
+			"not exists (select 1 from media_file_artists mfa where mfa.media_file_id = media_file.id and mfa.role = ?)", "artist"),
 		Entry("isMissing role [false]", criteria.IsMissing{"artist": false},
-			"exists (select 1 from json_tree(media_file.participants, '$.artist') where key='name')"),
+			"exists (select 1 from media_file_artists mfa where mfa.media_file_id = media_file.id and mfa.role = ?)", "artist"),
 		// isPresent — tags
 		Entry("isPresent tag [true]", criteria.IsPresent{"genre": true},
 			"exists (select 1 from json_tree(media_file.tags, '$.genre') where key='value')"),
@@ -80,9 +82,9 @@ var _ = Describe("Smart playlist criteria SQL", func() {
 			"not exists (select 1 from json_tree(media_file.tags, '$.genre') where key='value')"),
 		// isPresent — roles
 		Entry("isPresent role [true]", criteria.IsPresent{"composer": true},
-			"exists (select 1 from json_tree(media_file.participants, '$.composer') where key='name')"),
+			"exists (select 1 from media_file_artists mfa where mfa.media_file_id = media_file.id and mfa.role = ?)", "composer"),
 		Entry("isPresent role [false]", criteria.IsPresent{"composer": false},
-			"not exists (select 1 from json_tree(media_file.participants, '$.composer') where key='name')"),
+			"not exists (select 1 from media_file_artists mfa where mfa.media_file_id = media_file.id and mfa.role = ?)", "composer"),
 	)
 
 	Describe("playlist permissions", func() {
@@ -204,6 +206,146 @@ var _ = Describe("Smart playlist criteria SQL", func() {
 		}
 	})
 
+	Describe("JSON condition merging", func() {
+		It("merges multiple role conditions in an OR group into a single EXISTS", func() {
+			expr := criteria.Any{
+				criteria.Contains{"artist": "Beatles"},
+				criteria.Contains{"artist": "Kraftwerk"},
+				criteria.Contains{"artist": "Pink Floyd"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, args, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(Equal("(exists (select 1 from media_file_artists mfa join artist on artist.id = mfa.artist_id where mfa.media_file_id = media_file.id and mfa.role = ? and (artist.name LIKE ? OR artist.name LIKE ? OR artist.name LIKE ?)))"))
+			Expect(args).To(HaveExactElements("artist", "%Beatles%", "%Kraftwerk%", "%Pink Floyd%"))
+		})
+
+		It("does not merge role conditions from different roles", func() {
+			expr := criteria.Any{
+				criteria.Contains{"artist": "Beatles"},
+				criteria.Contains{"composer": "Lennon"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, _, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("mfa.role = ?"))
+			// Two separate EXISTS since roles differ
+			Expect(strings.Count(sql, "exists")).To(Equal(2))
+		})
+
+		It("does not merge negated role conditions", func() {
+			expr := criteria.Any{
+				criteria.NotContains{"artist": "Beatles"},
+				criteria.NotContains{"artist": "Kraftwerk"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, _, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			// Two separate "not exists" since they are negated
+			Expect(strings.Count(sql, "not exists")).To(Equal(2))
+		})
+
+		It("batches large groups to avoid SQLite expression tree depth limit", func() {
+			// Create jsonCondBatchSize + 1 conditions to trigger batching into 2 groups
+			anyExprs := make(criteria.Any, jsonCondBatchSize+1)
+			for i := range anyExprs {
+				anyExprs[i] = criteria.Contains{"artist": fmt.Sprintf("Artist%d", i)}
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: anyExprs}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, args, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			// Should produce 2 EXISTS subqueries (one batch of jsonCondBatchSize, one of 1)
+			Expect(strings.Count(sql, "exists")).To(Equal(2))
+			// First batch has jsonCondBatchSize patterns, second has 1 => total args:
+			// 2 roles + (jsonCondBatchSize + 1) patterns
+			Expect(args).To(HaveLen(2 + jsonCondBatchSize + 1))
+		})
+
+		It("merges role conditions while preserving non-role conditions", func() {
+			expr := criteria.Any{
+				criteria.Contains{"title": "Love"},
+				criteria.Contains{"artist": "Beatles"},
+				criteria.Contains{"artist": "Kraftwerk"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, args, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(ContainSubstring("media_file.title LIKE ?"))
+			Expect(sql).To(ContainSubstring("artist.name LIKE ? OR artist.name LIKE ?"))
+			Expect(args).To(HaveExactElements("%Love%", "artist", "%Beatles%", "%Kraftwerk%"))
+		})
+
+		It("merges multiple tag conditions in an OR group into a single EXISTS", func() {
+			expr := criteria.Any{
+				criteria.Contains{"genre": "Rock"},
+				criteria.Contains{"genre": "Metal"},
+				criteria.Contains{"genre": "Punk"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, args, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(sql).To(Equal("(exists (select 1 from json_tree(media_file.tags, '$.genre') where key='value' and (value LIKE ? OR value LIKE ? OR value LIKE ?)))"))
+			Expect(args).To(HaveExactElements("%Rock%", "%Metal%", "%Punk%"))
+		})
+
+		It("does not merge tag conditions from different tags", func() {
+			expr := criteria.Any{
+				criteria.Contains{"genre": "Rock"},
+				criteria.Contains{"mood": "Happy"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, _, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(strings.Count(sql, "exists")).To(Equal(2))
+		})
+
+		It("does not merge negated tag conditions", func() {
+			expr := criteria.Any{
+				criteria.NotContains{"genre": "Rock"},
+				criteria.NotContains{"genre": "Metal"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, _, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(strings.Count(sql, "not exists")).To(Equal(2))
+		})
+
+		It("merges role and tag conditions independently", func() {
+			expr := criteria.Any{
+				criteria.Contains{"artist": "Beatles"},
+				criteria.Contains{"artist": "Kraftwerk"},
+				criteria.Contains{"genre": "Rock"},
+				criteria.Contains{"genre": "Metal"},
+			}
+			sqlizer, err := newSmartPlaylistCriteria(criteria.Criteria{Expression: expr}).Where()
+			Expect(err).ToNot(HaveOccurred())
+
+			sql, args, err := sqlizer.ToSql()
+			Expect(err).ToNot(HaveOccurred())
+			// Two merged EXISTS: one for roles, one for tags
+			Expect(strings.Count(sql, "exists")).To(Equal(2))
+			Expect(sql).To(ContainSubstring("artist.name LIKE ? OR artist.name LIKE ?"))
+			Expect(sql).To(ContainSubstring("value LIKE ? OR value LIKE ?"))
+			Expect(args).To(HaveLen(2 + 2 + 1)) // 2 tag patterns + 2 role patterns + 1 role name
+		})
+	})
+
 	Describe("joins", func() {
 		It("excludes sort-only joins from expression joins", func() {
 			c := criteria.Criteria{Expression: criteria.All{criteria.Contains{"title": "love"}}, Sort: "albumRating"}