When playing the original 5-CD version of Baldur's Gate 1 on modern PCs, the ambient (non-combat) music almost never starts playing unless you force it to, by either quicksaving or by switching between window/fullscreen modes. It usually re-starts after combat music ends, but rarely continues to loop.

For example:
Start a new game in Candlekeep and walk in & out of the tavern behind you repeatedly: the tavern music should start playing every single time you enter, and it should keep looping as long as you stay inside.

At first I thought this problem is only CPU-speed related, because it's lessened if you slow down the game so much that it stutters badly. But I never had this music problem back on a Pentium-200 even though game was running smoothly.

Then I found a fix that only works on Win-XP (tested on Core-2-Duo, Intel graphics):
- Go to dxdiag.exe and completely turn off the sound acceleration slider.
- This ALMOST fixes the problem. You'll find the tavern music starting normally every time regardless of how fast & smooth the game is running, but there are other spots where it sometimes starts and sometimes doesn't, e.g. in the night walking cutscene with Gorion before the combat cutscene with Sarevok, or just when Imoen comes to join you after that ... etc.

Since the DirectX sound acceleration slider is missing from Win7 onwards, I have no solution other than to play BG1 on a Core-2-Duo PC.
Dual-booting to XP on 2nd & 3rd gen intel PCs didn't help: BG1 graphics run fine on those PCs in Win7, but their same GPUs stutter horribly on BG1 in WinXP (tested on Intel-HD graphics, Radeon 7850).

I've posted this over a decade ago on forums like GemRB, Beamdog for BG-EE, and Gibberlings ... etc. It just occurred to me to try here because some of the members here were smart enough to find assembly-level fixes for some DOS speed-sensitive games. Though it may be too late. I wonder how many people now even remember that BG-1 had music in every single indoor/outdoor area, unlike BG-2.

Note: I'm looking specifically for a solution for the 5-CD original BG1. I'm not interested in BG-2 engine total conversion mods (BGT / Tutu) or BG:EE.