The mysterious Geronimo Jackson was described this way on the ABC TV store:

Keith Strutter formed the rock band Geronimo Jackson in the mid 60s in Detroit. Gathering a solid reputation for their sold-out string of performances in local burlesque clubs, the band packed up their gear and made way to the Excelsior District of San Francisco. From there they released their first album “Magna Carta,” receiving much acclaim and star status to locals in the industry. Reported to be making their long awaited follow-up album, the band retired to Woodstock in 1972, never to be seen or heard again.

Interest in Geronimo Jackson surged during season 2 of Lost after a copy of their album was found in “the hatch” (or the Swan, as it’s also known) by Hurley and Charlie (who, as “an expert in all things musical,” had never heard of the band). Later on, posters for the band were seen in various episodes, and in the third season episode “Further Instructions,” a character is seen sportin’ a Geronimo Jackson t-shirt.

Now, some folks claim Geronimo Jackson never existed and the one-and-only song available by the band, “Dharma Lady,” was actually performed by a San Diego band called The Donkeys. Personally, I prefer to think Keith Strutter is still out there somewhere, working on a commune and planning a comeback.

Geronimo Jackson at Lostpedia