Losing voice polyphony in the music on my SNES

[gamer22747294]

I was playing Super Mario World on my SNES and in music effects or sequences, chords are missing a note or some notes just flat out don’t play. Could anyone explain what’s going on here?

[CommodoreDecker]

Does this happen to any other games? If so, chances are it's a hardware problem in the SNES.

 

If not, then does that cartridge get warm to the touch? (Even then, chances at this point are that the issue is with the ROM chips in the game cartridge...)

 

Is the SNES connected directly to the TV or is a receiver doing the audio amplification? (Depending on which notes and sequences, if they're the same ones, maybe there's a filter that's stripping out that frequency?)