This autobiographical musical by Jonathan Larson, creator of the megahit Rent, is a revised version of a one-man show he used to perform around New York. Set in 1990, it chronicles a struggling songwriter's anxiety about turning 30 without having achieved his dream of writing "the Hair of the 90s." It's a dream that Larson fulfilled at the age of 36 but didn't live to enjoy: on the eve of Rent's much anticipated opening, he died of an aortic aneurysm. Larson's untimely death gives extra poignancy to this engaging, tuneful portrait of the artist as a young obsessive, seen here in a touring edition of the hit off-Broadway production. Christian Campbell and Trey Ellett alternate in the lead role; I recommend seeing the superb Ellett, who performs in the matinees. Appealing Nicole Ruth Snelson and charismatic Wilson Cruz costar as the composer-hero's girlfriend and gay best pal, whose own changing lifestyles heighten the songwriter's pre-midlife crisis. As in Rent, Larson (clearly influenced by the likes of Elvis Costello and Cheap Trick) displays a knack for using rock idioms--pulsing rhythms, catchy melodic hooks--to dramatize believable, complex relationships onstage. Shubert Theatre, 22 W. Monroe, Chicago, 312-902-1400. Through May 25: Friday, 8 PM; Saturday, 2 and 8 PM; Sunday, 2 PM. $20-$57.