Spenner played bass live at Woodstock in 1969 with Joe Cocker and the Grease Band and can be seen on The Woodstock Directors CutDVD. In 1975, he played on Bryn Haworth's album Sunny Side of the Street. In August 1982, he played on Roxy Music's VHS/DVD The High Road, filmed live in Fréjus, France.
Spenner typically played Fender Precision, Fender Precision Fretless and Wal electric basses through an Ampeg amplification system. His Wal bass was a 78 JG Series that, coupled with his playing style, provided a signature sound heard on many Roxy Music songs, such as "Same Old Scene" and "Avalon".