How does one go about obtaining rights to use a piece of commercial music? Is it costly? Is it even worth it if I'm going to be doing children's shows on a small scale?

If you do a Google search on "music clearance" you'll discover a bounty of good information.

Here's a very brief overview.

To use a copyrighted composition in connection with the public performance of a magic act you need a performance license and a synchronization license from the publisher(s) of the composition. You can usually secure the performance license from the applicable performing rights society (in the US it's ASCAP or BMI), but you often have to contact the publisher directly for the synchronization license.

If you want to use a preexisting recording of the composition (as opposed to making a new recording of the composition or performing it live), you also need to secure a master use license from the record company.

You may likely get away with using the music (and recording) in the context of small children's shows without securing these licenses, but you would be violating copyright laws. I suggest you contact the appropriate entities, explain your situation and see if they will grant you conditional use licenses free of charge or for a small license fee. I make use of a song from an Off-Broadway musical in my stand-up act, and I did just that--I contacted the composer and lyricist of the song directly (at the direction of ASCAP), explained who I was and how I wanted to use their song, and was granted a free, conditional use performance and sync license. I then paid a professional pianist to make a recording of the song for me to use and, in that way, was able to avoid having to secure a master use license.

BTW--if you go that route and pay someone to make a recording of the music you want to use, be sure to have them sign an agreement stating that the result and product of their services is deemed a "work made for hire", that you are the owner of such result and product (the recording), that you have the right to use the recording, in whole or in part, in whatever manner you desire, and that no further compensation is due to them for your use of the recording.

Thanks for the info! I'll do that Google search, as well.

There is lots of royalty free music out there search Author Snead's web site he has lots of royalty free music that you can use as you see fit. Really good stuff. I think that it is the only way to go. That way you don't have to worry with all the legal stuff. Have Fun!!