As I said before, the point is to create a metronome. You can google what a metronome is. If you want to keep a certain rhythm, a metronome can help achieve it and you can pretty much input any integer value (upto a reason) for beats per minute. There are also many free metronome apps on Google app store that take an integer value and work pretty well. The actual BPM depends on the music written indicated by the tempo.
I was testing it with a few values of BPM to see how the timer and the player works. While looping with a discrete set of ogg files is a good idea if you have a few values (and is a useful tool to have in my toolbox), for arbitrary integer inputs within a range this method would not be practical.
Based on all the discussion so far, looks like AppInventor has certain limitations which makes the creation of a general purpose metronome metronome not possible.
Thanks for all the suggestions and code snippets.