Yes they can! The music is suitable for solo playing on any instrument. When played together, transposing instruments such as clarinet, trumpet or saxophone require specially written parts in order to play in tune with backing CDs and other instruments. Flutes, violins and other non transposing instruments can all play the music straight off the page in tune with Mini, Alto and Bass ocarinas, and with the Oc® .
Yes, if you are willing to experiment and write harmony parts, or play by ear. Try playing the tune on a D ocarina, and improvise harmonies with a G ocarina. The sound of two differently pitched ocarinas playing together can be wonderful. Ocarina charts are suitable for both D and G ocarinas, so groups of G ocarinas can play well together at their own pitch using the books. Masquerade Ocarinas play arrangements for D and G ocarinas. Videos of these can be seen on this site, and on YouTube.
To hear a virtuoso group listen to Michael Copley and the Chuckerbutty Ocarina Quartet on their CD ‘The ocarina is No Trombone’. ‘The Sweet Potato Tooters’ CD is also great fun. See the Music and CDs section in OcShop for details.