11. With these keyboard instruments too, strings are occasionally plucked or bowed by hand. 12. They are among the first concertos for keyboard instrument ever written. 13. However, difficulties continued as demographic changes and foreign competition slowed sales of keyboard instruments . 14. He used concert grand pianos and, occasionally, other keyboard instruments such as the harpsichord. 15. Libin pointed out that Adam designed only two stringed keyboard instruments , both for Catherine. 16. Another keyboard instrument used in the orchestra, as well as jazz, is the vibraphone. 17. The company produced guitars as well as keyboard instruments , microphones, amplifiers and even drums. 18. He also uses keyboard instruments to deliver more sentimental soundtracks to a good effect. 19. In live shows, McCluskey often plays bass guitar and occasionally, keyboard instruments and guitar. 20. In some popular music bands, keyboard instruments are used to play the bass line.
