Is ScummRev 2 or 3 not the proper tool to use to take out music from Monkey Island 1 and 2? I've been trying but it doesn't seem to work. Should I know better?

For monkey island 1 it depends on what version you have, if you have a cd version you almost certainly have the music as audio-tracks on the cd.

As for monkey2 you should be able to rip music fine, although if you are using XP you wont be able to play it from within scummrev.
Find a SOUN block and expand it
Inside you will usually find 2 blocks ROL and ADL
These are the same piece of music in Roland MT-32 format and Adlib format. Select one and click on 'save as mid' to save it in midi format.

Note that due to the nature of IMUSE and its cue's the midi will probably sound wrong, Scumm Rev cant fix this - its the way the music is stored within the game. You could either try and re-orchestrate the music yourself or just download it from one of the mojo sites such as highland productions.

As for whether to use ScummRev 2 or 3 my general rule is to use ScummRev2 unless theres something you cant do in it - in which case you can try 3.ScummRev3 has some new features implemented but is missing some of the features from ScummRev2 because it is unfinished.