Believe it or not, there really can be Orff without instruments. While much of the published literature focuses on the use of pitched and unpitched instruments, in reality, there is usually a major segment of class work devoted to singing, speech, body percussion and movement, all elements that can be experienced without instruments. Ostinato patterns, echo, improvisation and other techniques associated with the Orff approach are still possible and can be highly musical without instrument use. Here are a few ideas for using each mode of expression. Just this simple ostinato makes the entire nursery rhyme much more of a musical experience.
Word chains are an easy way to create and make excellent music.
Using a specific topic, list various related words. Choose several that have interesting rhythms and put them into an order within a phrase. Add an ostinato pattern to this and it will instantly become even more interesting. Canons, Rounds and Partner songs are excellent, obvious ways to work on vocal training and various musical concepts. A variation on this type of work is the use of vocal ostinato patterns.