diff --git a/lib/__tests__/ai-usage.test.ts b/lib/__tests__/ai-usage.test.ts
index 0e1419f..ee833f1 100644
--- a/lib/__tests__/ai-usage.test.ts
+++ b/lib/__tests__/ai-usage.test.ts
@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { kstDayStartISO, SAJU_DAILY_LIMIT, TAROT_DAILY_LIMIT } from '../ai-usage';
+import { kstDayStartISO, SAJU_DAILY_LIMIT, TAROT_DAILY_LIMIT, MUSIC_DAILY_LIMIT } from '../ai-usage';
 
 describe('kstDayStartISO', () => {
   it('KST 자정을 UTC로 환산한다 (KST 15:00 UTC = 당일 00:00 KST)', () => {
@@ -14,4 +14,7 @@ describe('kstDayStartISO', () => {
     expect(SAJU_DAILY_LIMIT).toBe(1);
     expect(TAROT_DAILY_LIMIT).toBe(3);
   });
+  it('음악 일일 제한 상수', () => {
+    expect(MUSIC_DAILY_LIMIT).toBe(1);
+  });
 });
diff --git a/lib/ai-usage.ts b/lib/ai-usage.ts
index cba8c1b..977ca65 100644
--- a/lib/ai-usage.ts
+++ b/lib/ai-usage.ts
@@ -2,7 +2,8 @@ import type { SupabaseClient } from '@supabase/supabase-js';
 
 export const SAJU_DAILY_LIMIT = 1;
 export const TAROT_DAILY_LIMIT = 3;
-export type AiService = 'saju' | 'tarot';
+export const MUSIC_DAILY_LIMIT = 1;
+export type AiService = 'saju' | 'tarot' | 'music';
 
 /** KST(UTC+9) 자정을 UTC ISO로. 오늘 사용량 집계 하한. */
 export function kstDayStartISO(now: Date): string {
diff --git a/supabase/migrations/2026-07-03-phase3a-music.sql b/supabase/migrations/2026-07-03-phase3a-music.sql
new file mode 100644
index 0000000..53ff02b
--- /dev/null
+++ b/supabase/migrations/2026-07-03-phase3a-music.sql
@@ -0,0 +1,23 @@
+-- Phase 3a (2026-07-03): 음악 회원 저장 + 사용량 로그 확장 + 음악 숨김 해제
+-- 의존성: 2026-07-02-phase2-saju-tarot.sql(ai_usage_log 생성) 적용 후 실행
+-- 적용: 클라우드 Supabase + NAS self-host 양쪽
+
+CREATE TABLE IF NOT EXISTS music_tracks (
+  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+  user_id uuid NOT NULL REFERENCES auth.users(id) ON DELETE CASCADE,
+  title text,
+  story text,
+  lyrics text,
+  style text,
+  audio_url text,
+  task_id text,
+  created_at timestamptz NOT NULL DEFAULT now()
+);
+ALTER TABLE music_tracks ENABLE ROW LEVEL SECURITY;
+CREATE POLICY music_select_own ON music_tracks FOR SELECT USING (auth.uid() = user_id);
+
+-- ai_usage_log CHECK에 'music' 추가 (phase2의 인라인 CHECK auto-name 제거 후 재정의)
+ALTER TABLE ai_usage_log DROP CONSTRAINT IF EXISTS ai_usage_log_service_check;
+ALTER TABLE ai_usage_log ADD CONSTRAINT ai_usage_log_service_check CHECK (service IN ('saju','tarot','music'));
+
+DELETE FROM service_settings WHERE id = 'music';