Good point uke5417.
Actually, Bb, Eb, and F, are your standard "three chord" chords in the key of Bb. They're the I, IV, and V chords. So any other three-chord song using just the one, four, and five--of which there are
probably thousands--could be transposed to the key of Bb for a great Bb & Eb workout.
If you wanted to tackle the Ab chord too, then you could put the song in Eb, which would make those three magic chords Eb, Ab, and Bb. Ouch!
Here's a handy chart showing the I, IV, and V chords in those keys and in several common "uke keys":
Code:
I IV V
Bb Eb F
Eb Ab Bb
C F G
D G A
F Bb C
G C D
A D E
Just find the row that contains the three chords in your song. Substitute the corresponding chords that are in another row to transpose. If your V chord has a 7 after it, feel free to keep that 7 on the new chord too (or not... up to you!).
JJ