It's not as correct to say that Kelly imitates Joni Mitchell as it is to say that he channels her spirit as an artist. (He even dubs Zecca Esquibel and Paul Ossola, the on-stage musicians, as Georgia O'Keefe and Vincent Van Gogh, respectively). While he does replicate the singer-songwriter's vocals to near perfection while cross-dressed in a blonde wig, he doesn't and doesn't seem to want to completely vanish behind the illusion.
For example, he speaks his banter between songs sometimes as Mitchell but almost as often as himself. Although he may take a few isolated moments to imitate the way that Mitchell might shyly approach the microphone or savor a drag on a cigarette, he doesn't typically traffic in her mannerisms or facial expressions. There is some physical mimicry but the show is more about summoning Joni Mitchell through the slavishly faithful recreation of her songs.
Presented as a concert and directed by Kevin Malony, the show glides from one of Mitchell's gems to the next with Kelly usually accompanying himself on one of the guitars that dot the stage. (Assumedly, there are several at the ready so that Kelly needn't spend stage time turning knobs to deal with Mitchell's famously unique tunings). The song set in the first act, which confines itself to early songs in Mitchell's songbook including "Chelsea Morning," "For Free," and "Conversation," (though not "Big Yellow Taxi"), which shows Kelly's voice to dazzling advantage as he climbs up and down Mitchell's scales effortlessly. That's a considerable technical accomplishment, especially since Kelly does the songs in their original keys. But it's more than just that, as he's able to put personal feeling into his delivery even while limited to Mitchell's exact phrasings and canary-like trills.
In the second act, which includes songs from the last couple of decades including two songs from Mitchell's acclaimed comeback album "Turbulent Indigo," a costume-changed Kelly adopts a deeper, smokier voice to effectively summon the harder-edged Joni of more recent vintage. The show's coup de theatre comes during the second half of "Down To You," an epic art song from "Court And Spark," when Kelly sheds his Joni drag mid-song and performs as himself. The moment has a surprising impact and seems to dramatize the profound transformative effect of art on its beholder.