SMB3 strange 1-up sound

[MEGAߥTE]

Not quite.  It combines the lengths of the 1UP and tail wag sound, but starts playing from the 1UP location.  Whatever comes before the 1UP data is also played, but that's not necessarily the tail wag data, nor is it "extended" 1UP sound data, just some other random data.

[Mega 2]

That makes sense.  You should have said it before.

[Chupperson Weird]

From the first post:
"The 'glitch' involves the tail wag sound effect and the 1-up sound effect's calls getting merged. The sound code reads both, treats it like a 1-up sound effect, but writes the wrong length, so it plays more notes than it should."