Live PA artists typically add to these sequenced and triggered parts with hand-played electronic keyboards, hand-triggered audio samples, live vocals/singing, and other live instruments. Some artists like Brian Transeau and Jamie Lidell utilize hardware and software tools custom-designed for live expression and improvisation. By arranging, muting, and cueing pre-composed basic musical data (notes, loops, patterns, and sequences), the live PA artist has the freedom to manipulate major elements of the performance and alter a song's progression in real-time. As such, each performance may be different, as the live PA artist changes the loops and patterns.