Smith is the former frontman of 1970s progressive rock act Crystal Ship (which is also the title of a song by The Doors), and it is fairly obvious from listening to his radio broadcasts that he thought pretty highly of the group, especially his contributions to it. It is not known when the group dissolved or if they were still active by 1992, the year Grand Theft Auto: San Andreas is set. Smith is surprisingly calm and constantly reminds the listeners about the 70s and the classic "Rock 'n Roll lifestyle".
Tommy is voiced by Guns N' Roses frontman Axl Rose. Smith's history could be a jab at Rose himself. Like Rose, Smith's music career has dried up (Crystal Ship is without him; Guns N' Roses, with almost a completely new lineup, have faded from popularity). Also, his former bandmates are much more successful (Rose's former bandmates have moved on with Velvet Revolver as well as solo projects, and have achieved higher success than Rose—Former members of Guns N' Roses are now in the Hall of Fame, while Rose declined his invitation). And like Rose, Smith is reduced to a much less glamorous job, being a DJ (and Rose is reduced to voicing a DJ in a video game) Whether or not these are intentional or a coincidence is unknown, but it's likely Rose hasn't made the connection, as he is notorious for requiring everything to suit him and would most likely quit if he felt he was being mocked.
Tommy and Sage, who is the host of alternative rock station Radio X, appear to hold grudges against each other, presumably for dislike of the other's musical preferences. On air, Smith tells her to "get over it!" during the intro to Tom Petty's "Runnin' Down a Dream", which is ironic because Sage states on Radio X that she "slept with this guy once" before Guns N' Roses' hit "Welcome to the Jungle" (which Rose was credited to creating) commences.