If dying is easy and comedy is hard, then improv is darned near impossible. In his studious but breezy book, "Improv Nation: How We Made a Great American Art," author Sam Wasson tracks the relatively young craft of creating humor in the same time it took Neil Simon to sharpen a pencil, making readers feel like they're sweating on stage with its quick-witted practitioners.

Like the best of his subjects, which include Stephen Colbert, Bill Murray and Tina Fey, Wasson has perfect timing, publishing just as stand-up comedy enjoys a Golden Age and "Saturday Night Live" delivers stellar ratings. He also managed to sit down with "Groundhog Day" director Harold Ramis and EGOT (Emmy, Golden Globe, Oscar, Tony) winner Mike Nichols days before each passed away.

Nichols, and his partnership with Elaine May, is very much the heart of this wide-ranging exploration, detailing how their yin-and-yang chemistry sizzled in clubs and eventually seeped into pop culture. In the early pages, it's hard to figure out why every co-star fell madly in love with May. By the time you get to the anecdote about how she hijacked the valiant flop "Mikey and Nicky," you'll be crushing on her, too.

Wasson, who has also written books on Blake Edwards and Bob Fosse, takes you behind the scenes of May's "The Heartbreak Kid," shot largely in Minnesota, as well as "Animal House," Caddyshack" and other classics that relied more on instinct than finely tuned scripts.

The author dives into television as well, with a unapologetic preference for "SCTV," where performers including John Candy and Catherine O'Hara had a much freer hand than the Not Ready for Prime Time Players under the thumb of "Saturday Night Live" producer Lorne Michaels. In the process, Wasson makes a compelling argument that Joe Flaherty may be comedy's most underappreciated workhorse.

But the main focus is on live performances in Chicago and New York, where everyone from Dustin Hoffman to Amy Poehler lined up to take a walk on the high wire (sorry, folks; no mention of the Twin Cities' 59-year-old Brave New Workshop).

Wasson doesn't shy away from the tragic elements that too often accompanied such a high-demanding craft. The drug and alcohol use that haunted John Belushi and teacher Del Close, the Sonny Corleone of the Second City mafia, has been explored before, but never with such depth and sympathy.

Wasson has far less to say about the lack of diversity in the improv world. More on the influence of "In Living Color" and the recent success of "Key & Peele" would have made sense. He also opted to leave out early stand-up pioneers such as Mort Sahl, who would often use the morning paper as his inspiration, and Jonathan Winters, who could conjure up an entire troupe all by his lonesome.

Those shortcomings aside, Wasson has assembled a loving tribute to one of entertainment's most daunting challenges, with lots of laughs to boot.

Neal Justin is the Star Tribune's television critic.

Improv Nation
By: Sam Wasson.
Publisher: Houghton Mifflin Harcourt, 449 pages, $28.