By rights, Alan Henderson should be one of the better-known bandmembers and sidemen to come out of the British Invasion. As the bassist for Them working alongside vocalist Van Morrison, he was -- along with Morrison -- among the few actual group members to play on all of their recordings during their heyday (and long after). Henderson was born in Belfast, Northern Ireland, in 1944, and in his late teens aspired to a music career. In 1962, he was recruited into the Gamblers, a Belfast-based band (not to be confused with the similarly named group that later backed Billy Fury) founded by guitarist Billy Harrison. With Ronnie Millings as their drummer and pianist Eric Wrixon coming aboard a little later, the group specialized in hard American-style rock & roll and R&B, with a repertory that included both Elvis Presley and Little Willie John. It was sometime after Wrixon joined that he and Harrison crossed paths with singer/sax-player Van Morrison, and not long after that -- depending on whose story one believes -- either Morrison joined the Gamblers or they agreed to become his backing band. And as Billy Fury was already backed by a group called the Gamblers, they were forced to change their name in order to have a chance of getting heard in England, and they became Them.
Over the next three years, the band went through 16 personnel charges, sidemen exiting and being replaced on a weekly basis. It was sufficiently confusing to their record label so that most of the working members of Them weren't even permitted to play on their records -- Morrison sang and Henderson played bass on everything, but virtually every other contributor to their sound was a session musician hired for the occasion. That being the case, their music across that time was amazingly consistent, and Henderson's playing was a match for the best work on those records. Henderson ultimately became the force holding what was left of the group together, following Morrison's departure. If only by default, as the last active original member at that moment, he had use of the name (a situation clarified by an eventual court ruling against a rival group, made up of musicians who had passed through their lineup), and he put together a string of latter-day versions of Them. There were numerous cash-in attempts using the name or variations thereof, of which the one under Henderson's leadership was the most prominent. They moved to America in 1967 and recorded a pair of psychedelic albums during this period that gave them an edge over most of their rivals and competitors for the legacy -- though it must be conceded that the Belfast Gypsies, featuring ex-Them guitarist Jackie McAuley as lead singer, may have outclassed Henderson's group in the voice department. Competing with various other related outfits, Henderson kept the Them franchise going well into the '80s, far longer than one would have expected for a group with a relative handful of hits from the '60s to fuel recognition and demand. Since the start of the '90s, several ex-bandmates -- coalescing around Harrison -- have organized themselves as the Belfast Blues Band, which does the same kind of R&B-based music that Them used to do, only with far greater skill. Henderson, for his part, retired from music after the '80s.