I am playing Ultima IV in iMac. Is there any way to get the music I used to listen in old plataforms like Windows many years ago?
Thanks,

Antonio

Ultima IV you play on Mac is basically the DOS version, run via DOS emulator. Unfortunately the DOS version of Ultima IV doesn't include music.
However you can download a mod called Ultima IV Upgrade that adds music (and improve graphics). If you prefer, you can use this useful utility to patch the game.
You may also want to try Ultima IV Recreated, a remake of the game's engine.

I strongly suggest you to read this post that clearly explains how you can patch the game on MacOs in order to add music playback.

Another solution is to get an Apple II emulator. Then you can play the original Ultima IV, with the original music.

Virtual II works very well and gives you the full Apple II 'experience'

There is also Apple2Mac and AppleCommander, which are more basic, but work quite well.

The disks for Ultima IV are readily available on dozens of archive and preservation sites.