I have quite a list of games here with bgm. Here goes:
Big Bird's Egg Catch, Cookie Monster Munch, Oscar's Trash Race (quality tunes for Atari's Sesame Street lineup)
Bump n Jump, Pengo, Phoenix (all three utilize difficulty or color/bw switches to turn off or on)
Congo Bongo, Crossbow (jungle level), Holey Moley, Jungle Hunt (Cannibal Camp level), Mr. Do's Castle, Omega Race, Pleiades (1st level), River Patrol, Roc n Rope, Xevious - latest prototype (arcade conversions
Cabbage Patch Kids Adventures in the Park, Peek-a-Boo, Secret Agent, Shooting Arcade, Telepathy (fish level), Pursuit of the Pink Panther (prototypes)
Bugs, Fire Fly, Gauntlet, Krull (1st level), Piece o' Cake, Sorcerer (weird and questionable)
King Kong, Raiders of the Lost Ark (when holding flute), Sentinel, Sneak n Peek (interesting as there is only music, no sound effects), Tunnel Runner (when monsters are close)
Challenge, Farmyard Fun, Forest, Lilly Adventure, MegaBoy, Mr. Postman, Panda Chase, Parachute, Peter Penguin, Pizza Chef, Ski Hunt, Ski Run, Stone Age, Treasure Island, Walker, Zoo Fun (foreign releases)