It is generally assumed that when you want to overflow (or underflow) to an area, you can't use the same theme without said theme reloading itself.

This is partly true, however there is a way to circumvent this:
_If the area you want to load is not part of the current level, you can still use the same theme from the area Mario just left without having the music to reload IF and only IF the area you want to over/under-flow to is the first area of its original level.


For example:
_if you underflow from Level 5-1 Area 1 to Level 1-2 Area 2, the Grassland theme will restart;
_but if you underflow from Level 5-1 Area 1 to Level 2-2 Area 1 then the Grassland theme will continue without reloading.


I just wanted to clear that common, albeit not totally incorrect, misconception.

Interesting, albeit the use of this is pretty limited, as you'd have to find an area that uses the tileset/bg combination you want.

Buut, I guess there is a couple areas that you can use without worrying about that; the Mario vs Luigi levels and the unused World 6 cannon. Unless those don't count as "Area 1"

Actually they do count, in fact if an area is the only one of its native level, then it is definitely eligible for the trick.

This reminds me of some things. In W2-6, if you go through the pipe which brings you to the view with the End Level Flag, the Mushrooms-music reloads itself.

And in W2-Castle, if you go through the Boss Door, in Area 3 the castle music begins, but you can hear it only for a second, and then you hear the castle ambience.

I can explain both conundrums:

The Mushrooms music reloads for Level 2-6 Area 1 View 2 because Area 1 have 2 views with different themes.
Had the View 1 been assigned the Mushrooms music instead, this "glitch" wouldn't happen and the music would flow without interruption from the beginning to the end.

For the Level 2-Castle, this is caused by the ?-Switch music stopping abruptly, the game still has memory of the previous soundtrack hence why you can hear the Castle theme for a split second (not always though).

Ah, I see. It's nice that I understand how this works now.

Lolbump!

...But seemingly, there's exceptions to the rule. Going from 5-1 to ANYWHERE with a different music set won't work. Meanwhile, going from 5-1 to somewhere with the same music won't restart it, even if it's not the first area of a level.

groans
It annoyed me, since I wanted a sekrit area in 5-1.