No one burns bridges with as much unwitting determination as Goodbye Time Bomb's David McGhee — except for maybe Roky Erickson and Daniel Johnston. While he's not in the same league as those two genius songwriters, McGhee does share a frustrating knack for self-implosion. Known mainly for peppy, punky pop songs delivered with a sometimes excruciatingly nasal vocal delivery, the driving force behind Goodbye Time Bomb is a surprisingly talented lyricist. When he can resist crossing over into faux-snotty punk-rock territory, it becomes clear that the guy can sing, and his intense, utterly honest words of self-reflection and observation are simply striking. In many circles, McGhee may be considered persona non grata for his eccentric antics: On and off stage, he can come across as needy, fragile and on the verge of coming off the rails. But at his lucid best, with the Milkshakes, his previous project, and Goodbye Time Bomb (due at the Larimer Lounge on Sunday, August 5), his songs illuminate the human condition and offer glimmers of existential truth.