In 1966, Eric Burdon, frontman for The Animals, put together a new Animals lineup when the original group, with the exception of drummer Barry Jenkins, ceased working with Burdon. The new group, variously called "Eric Burdon and the New Animals" or "Eric Burdon and the Animals", included Weider on guitar and violin. The first album by the new ensemble was the 1967 effort Winds of Change, in which the Animals abandoned their old blues sound and went psychedelic. Weider stayed with the group until its dissolution in December 1968, recording The Twain Shall Meet, Every One of Us, and Love Is, the latter being a soul-based psychedelic rock album. After bassist Danny McCulloch and guitarist Vic Briggs were fired from the band in mid-1968, Weider and new guitarist Andy Summers alternated between guitar and bass during the band's concerts.
Family
By 1969, Weider was in California playing in a group called Stonehenge, members of whom would later form Crabby Appleton, when Ric Grech abruptly left Family to join Eric Clapton, Steve Winwood and Ginger Baker in the new 'supergroup' Blind Faith during Family's first U.S. tour and the band needed a new bassist immediately. Weider thus replaced Grech in Family. Like Grech, he was both a bassist and a violinist, and many of Family's songs had incorporated violin in their arrangements. Weider joined midway through the tour, which ended prematurely owing to lead singer Roger Chapman's visa problems, and a fight with rock promoter/venue owner Bill Graham, which made return visits to the U.S. difficult. The single "No Mule's Fool", Family's first single with Weider as a band member, took the band in a country rock direction. Weider appears on Family's two 1970 albums, A Song for Me and Anyway released ten months apart. He left the band in the summer of 1971.
Later career
Weider later joined Stud, a group that featured guitarist-bassist Jim Cregan, who would become Family's final bass player in 1972. The band also included the rhythm section of John Wilson and Richard McCracken from Taste, Rory Gallagher's pre-solo power trio. Weider served as a multi-instrumentalist in Stud, playing guitar, bass, piano, violin and cello. After Stud broke up, Weider did some session work and released his self-titled debut solo album in 1976. In the mid 1970s, he was also a member of the band Moonrider with Keith West. In 1979, he was featured on Gulliver's album "Ridin' the Wind". Weider's more recent albums are more closely associated with New Age music.