Sonic Adventure had a FANTASTIC soundtrack. The music was catchy, fun and fitting to each level. This is the soundtrack list from the OST CD:

Disc 1

01. Introduction ...featuring "Open Your Heart"
02. Welcome to Station Square
03. Event: Strain
04. Boss: CHAOS ver.0, 2, 4
05. Azure Blue World ...for Emerald Coast
06. Windy and Ripply ...for Emerald Coast
07. BIG fishes at Emerald Coast
08. and... Fish Hits!
09. Hey You! It's Time to Speed Up!!!
10. Twinkle Cart ...for Twinkle Park
11. Pleasure Castle ...for Twinkle Park
12. Twinkle Circuit
13. Fakery Way ...for Twinkle Park
14. Run Through the Speed Highway ...for Speed Highway
15. Goin' Down!? ...for Speed Highway
16. At Dawn ...for Speed Highway
17. Choose Your Buddy! -Slap Bass ver.-
18. Theme of "CHAO"
19. Letz Get This Party Started ...for CHAO Race Entrance
20. Join Us 4 Happy Time ...for CHAO Race
21. The Dreamy Stage ...for Casinopolis
22. Blue Star ...for Casinopolis
23. Dilapidated Way ...for Casinopolis
24. Challenge for Another Aim
25. Theme of "Dr.EGGMAN"
26. Egg Mobile ...Boss: Egg Hornet
27. Mystic Ruin
28. Windy Hill ...for Windy Valley
29. Tornado ...for Windy Valley
30. The Air ...for Windy Valley
31. Fight for My Own Way ...Boss: Event
32. Snowy Mountain ...for Icecap
33. Limestone Cave ...for Icecap
34. Be Cool, Be Wild and Be Groovy ...for Icecap
35. Invincible ...No Fear!
36. Choose Your Buddy! -Finger Bass ver.-

Disc 2

01. Mt. Red: a Symbol of Thrill ...for Red Mountain
02. Red Hot Skull ... for Red Mountain
03. Heartless Colleague ...Boss: E-Series Targets
04. Sand Hill
05. Event: Sadness
06. Theme of "TIKAL"
07. Tricky Maze ...for Lost World
08. Danger! Chased by Rock ...for Lost World
09. Leading Lights ...for Lost World
10. Event: The Past
11. Event: Fanfare for "Dr.EGGMAN"
12. Tornado Scramble ...for Sky Chase
13. Funky Groove Makes U Hot!? ...for Options
14. Egg Carrier - A Song That Keeps Us On The Move
15. ZERO The Chase Master ...Boss: Eggman Robot -ZERO-
16. Skydeck A Go! Go! ...for Sky Deck
17. General Offensive ...for Sky Deck
18. Theme of "E-102y"
19. Crazy Robo ...Boss: E-101R
20. Bad Taste Aquarium ...for Hot Shelter
21. Red Barrage Area ...for Hot Shelter
22. Danger is Imminent
23. Sweet Punch ...for Hedgehog Hammer
24. Militant Missionary ...Boss: Egg Walker & Egg Viper
25. Mechanical Resonance ...for Final Egg
26. Crank the Heat Up!! ...for Final Egg
27. Boss: CHAOS ver.6
28. Calm After the Storm ...Egg Carrier -the ocean-
29. Event: Unbound
30. Perfect CHAOS Revival! ...Boss: Perfect CHAOS
31. Event: Good-bye!
32. Will You Continue?
33. Open Your Heart -Main Theme of "SONIC Adventure"-

Unincluded was the theme to NiGHTS Pinball (Casinopolis) and some short sound themes that can be heard in the Sound Test.