The textbook contains 9 trios that are roughly sequenced based on their difficulty, the introductory trios are very easy and therefore suitable for introduction with interplay in a chamber ensemble.
In all the trios there is the drum set present. Other than that you can find here tom-toms, bongos, wood blocks, a cowbell, but also an agogo bell, a tambourine and maracas. The last four trios contain also a melodic instrument - a xylophone or a glockenspiel. Parts for these instruments are written in a simple melodic and rhythmic style so that it corresponds with the difficulty of other parts and doesn't vitiate the overall conception.
I hope that these basics for chamber ensemble interplay contain interesting material that can engage both players and listeners and that it doesn't discourage them from more demanding compositions. If you want more practice, I can recommend publications on quartets for percussion as a sequel to these trios.