Indeed, almost all Play Station portings from SNES as far as I know have lesser sound ( CT, FFV, FFVI, Tales of Phantasia, Tactics Ogre and anymore?). FFVI for PS1 would be the exception, but I guess it was streamed. PS1 has 8 times more memory space, 3 times more channels and higher sampling rate than SNES, but it never means PS1 can sequence SNES music better.
Strictly speaking, CT and other games's music for PS1 were not emulated but sequenced by PS1 synth. If PS1 could emulate or stream SNES music, we would have heard the very same music as SNES. However, PS1 didn't have enough power to even render 2D visuals with fast reading time. So, they couldn't read individual instrumental data from CD-ROM, While SNES could read them from their ROM cartridge immediately.
Well, but, I'm not a game developer. Don't believe me.
Jam it back in, in the dark.