Noun
bastarda (uncountable)
A type of simplified Gothic script used primarily in continental Europe during the fourteenth and fifteenth centuries.
Although most diminutions are written for organ, string instruments or cornett, Suzanne is "per violone over Trombone alla bastarda". Source: Internet
Besides consort playing the bass could also be used as a solo instrument (there were also smaller basses designed especially for a virtuosic solo role, see above division viol, lyra viol, viola bastarda). Source: Internet
The term "bastarda" describes a technique that made variations on all the different voices of a part song, rather than just the melody or the bass: "considered illegitimate because it was not polyphonic". Source: Internet