diff --git a/backend/__pycache__/config.cpython-312.pyc b/backend/__pycache__/config.cpython-312.pyc
new file mode 100644
index 0000000..fd64420
Binary files /dev/null and b/backend/__pycache__/config.cpython-312.pyc differ
diff --git a/backend/main.py b/backend/app.py
similarity index 100%
rename from backend/main.py
rename to backend/app.py
diff --git a/backend/db.py b/backend/db.py
index 998f5ac..6c9f44e 100644
--- a/backend/db.py
+++ b/backend/db.py
@@ -1,4 +1,5 @@
 from config import db
+from datetime import datetime
 
 # Association tables
 song_artist = db.Table(
@@ -13,17 +14,57 @@
     db.Column('genre_id', db.Integer, db.ForeignKey('genres.id'), primary_key=True)
 )
 
+class Playlist(db.Model):
+    __tablename__ = "playlists"
+    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
+    spotify_playlist_id = db.Column(db.String(100), nullable=False)
+    name = db.Column(db.String(200), nullable=False)
+    description = db.Column(db.Text, nullable=True)
+    user_id = db.Column(db.Integer, db.ForeignKey('users.id'), nullable=False)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+
+
+
+    #relationships
+    user = db.relationship('User', back_populates='playlist')
+    songs = db.relationship('Song', back_populates='playlist')
+    recommendations = db.relationship('Recommendation')
 class Song(db.Model):
-    __tablename__ = "Songs"
+    __tablename__ = "songs"
     id = db.Column(db.Integer, primary_key=True, autoincrement=True)
-    tempo = db.Column(db.Integer, nullable=False)
+    spotify_id = db.Column(db.String(100), unique=True, nullable=False)
+    name = db.Column(db.String(200), nullable=False)
+    
+    # Audio features for Gemini analysis
+    tempo = db.Column(db.Float, nullable=True)
+    danceability = db.Column(db.Float, nullable=True)
+    energy = db.Column(db.Float, nullable=True)
+    valence = db.Column(db.Float, nullable=True)
+    acousticness = db.Column(db.Float, nullable=True)
+    instrumentalness = db.Column(db.Float, nullable=True)
+    liveness = db.Column(db.Float, nullable=True)
+    loudness = db.Column(db.Float, nullable=True)
+    speechiness = db.Column(db.Float, nullable=True)
+    key = db.Column(db.Integer, nullable=True)
+    mode = db.Column(db.Integer, nullable=True)
+    time_signature = db.Column(db.Integer, nullable=True)
+    
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+    
+    # One-to-many relationship with playlist
+    playlist_id = db.Column(db.Integer, db.ForeignKey('playlists.id'), nullable=False)
+    playlist = db.relationship('Playlist', back_populates='songs')
+    
+    # Many-to-many relationships
     artists = db.relationship('Artist', secondary=song_artist, back_populates='songs')
     genres = db.relationship('Genre', secondary=song_genre, back_populates='songs')
 
 class Artist(db.Model):
     __tablename__ = "artists"
     id = db.Column(db.Integer, primary_key=True, autoincrement=True)
-    name = db.Column(db.String, nullable=False)
+    spotify_id = db.Column(db.String(100), unique=True, nullable=False)
+    name = db.Column(db.String(200), nullable=False)
+    #Many to many
     songs = db.relationship('Song', secondary=song_artist, back_populates='artists')
 
 class Genre(db.Model):
@@ -31,3 +72,16 @@ class Genre(db.Model):
     id = db.Column(db.Integer, primary_key=True, autoincrement=True)
     name = db.Column(db.String, nullable=False)
     songs = db.relationship('Song', secondary=song_genre, back_populates='genres')
+
+class Recommendation(db.Model):
+    __tablename__ = "recommendations"
+    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
+    playlist_id = db.Column(db.Integer, db.ForeignKey('playlists.id'), nullable=False)
+    seed_song_id = db.Column(db.Integer, db.ForeignKey('songs.id'), nullable=False)
+    recommended_song_id = db.Column(db.Integer, db.ForeignKey('songs.id'), nullable=False)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+
+    # Relationships
+    playlist = db.relationship('Playlist', back_populates='recommendations')
+    seed_song = db.relationship('Song', foreign_keys=[seed_song_id])
+    recommended_song = db.relationship('Song', foreign_keys=[recommended_song_id])