Most Sonic games have really good music and the series also has a good variety of music genres too. Not every song that was made for the series was put into the game though or is accessible through normal gameplay, and other songs were heavily changed in other releases of said game. From cut levels to issues with getting permission from certain musical artists, certain pieces of Sonic music had to be removed or changed.
D-Pad Video on Sonic 3: • A Brief History of Mic...
00:00 - 00:53 Intro
00:54 - 02:01 Sonic 2 (Hidden Palace Zone)
02:02 - 06:08 Sonic 3 (Carnival Night, Ice Cap, Launch Base, and Others)
06:09 - 07:34 Other Classic Era Songs
07:35 - 09:58 Shadow the Hedgehog (Broken and Who I Am)
09:59 - 12:31 Other Cut Songs