What exactly defines them, Is it the same pattern that just keeps repeating itself? Im a bit unclear.
Oxford Dictionary of Music : (It.) Obstinate persistent. A persistent musical phrase or rhythm. A basso ostinato is a figure in the bass which is persistently repeated.
My ol' college prof used Chicago's "25 Or 6 To 4" as an ostinato example- l1&2&3___l1&2&3___l1&2&3___l(1&2&3&4&l) lAAAAA___lGGGGG___lGbGbGbGbGb___l(FFFFEEEEl) I like Ed's "same notes under a changing harmony" thingee, too. Play a groove hard & consisent...let the guitarist go off wherever he hears fit(e.g. Check out Steve Khan's Eyewitness band w/ Anthony Jackson).
One beautiful example is from Herbie Hancock's 'Mwandishi' album. 'Ostinato: Suite for Angela' has Buster Williams on bass and Benny Maupin on bass clarinet laying out the figure. Thick.
