He is widely known to be instrumental to ZZ Top's success, having constructed their entire image and run all their publicity as well as produced all their albums and all their stage show productions. Ham is widely considered in the music business, and by the band itself, as sort of an invisible "4th member" of the trio.
He is also legendary for having managed to get the band some exceptionally good record deals, including a reported $35,000,000 guarantee from RCA. Ham ran his own recording label briefly in the 1960s, Scat Records.
He is a major figure in Nashville, starting with his discovery and management of vocalist Clint Black and his founding of several music publishing companies. At one point, his companies were publishing 5 of the top 10 country music hits.
While most of Ham's career has been managing and producing ZZ Top, he made a record of his own as a crooner for Dot Records before becoming ZZ Top's manager. His producer was Pat Boone. Ham has also produced such artists as Kinky Friedman and Point Blank.