A Welsh bass guitarist who gained fame playing primarily rock and roll, blues rock and rhythm and blues music, although he has been lauded for his ability to play most genres of popular music, including jazz, neo soul and funk. His career has spanned several ensembles, including the John Mayer Trio. He was also Pete Townshend's and Roger Daltrey's first choice to fill the position left by John Entwistle as the bassist for The Who. Adding to an eclectic grasp and melodic approach on his instrument, he has become one of the most sought-after session players on the bass and has played on a large number of recordings by some of the world's most successful entertainers.