Ever since Darren Criss surged into public consciousness last year on "Glee," the actor-musician-composer hasn't done much in half-measures, and his arrival in New York for a run in the Broadway hit "How to Succeed in Business Without Really Trying" was no exception. After hopping a plane immediately following his final 2011 shooting day on "Glee," he'd already played two vastly different shows in the city in a less than a 24-hour span.

Criss's first stop was Lincoln Center Saturday night, as the featured performer for the Yale Whiffenpoofs' "Sing Out, Raise Hope" benefit for The Trevor Project and the Elizabeth Glaser Pediatric AIDS Foundation. Criss followed performances by the Whiffs (with particularly stand-out solos from John Yi, who lead the group on a phenomenal "On Broadway" that should earn him his own spot on the Fox show) and Yale alum Allison Williams, in addition to Harvard and Princeton club performances. Criss, dressed in a sleek nerd-chic all black with a splash of red tie ensemble, joined the Whiffs for a version of "Teenage Dream" that was somewhere between the TV show style and the more relaxed versions Criss has been performing at various events in the past year.

From there he moved on to a very verbose set, dotted with equal parts music and banter, with Criss explaining who he is for the assembled guests, a mishmash of Yale alums, professors (and their children) and the assorted fans who dropped the hefty charity donation to attend.

The mixed bag led to a lot of room for Criss to define himself, and a set that was dominated by covers (the Britney Spears classic "Baby One More Time" merged with "Fur Elise" to fit the setting, Disney standard "A Whole New World"), tunes that showed off his musical-writing cred as part of his Team Starkid production company ("The Coolest Girl," "To Have A Home"), and "Glee" numbers that highlighted his leading-man status ("Something's Coming," "Baby It's Cold Outside," a duet with the normally non-verbal Brad Ellis, better known as "Glee's" pianist.)

Even Alice Tully Hall's iconic setting along Broadway served to remind that his arrival in town was not merely an extended vacation; Criss will take over Daniel Radcliffe's lead role in "How To Succeed In Business Without Really Trying" next month, and is packing his holiday break with rehearsals for the three-week run. In all, Criss expects to be in the Big Apple for about six weeks. Everything about Saturday worked to transform new converts into warm bodies just down the road come Jan. 3

Sunday was a different animal -- a Toys For Tots charity pop-up event that Criss only announced details of five hours before curtain, prompting die-hard fans in the city to rush to Joe's Pub last minute to pick up one of the precious 100 tickets available for a mere ten dollars plus a donated gift. Criss was joined by fellow University of Michigan alumni Theo Katzman and Charlene Kaye, both gifted performers and New York residents who shined in their own rights during opening acts, and served as appreciated supporters during Criss's set. Another special guest was Criss's brother, Chuck, who has found his own success as part of indie-outfit Freelance Whales. The two recorded Bob Dylan's "New Morning" for an Amnesty International compilation this Fall and sang the tune together both nights of Criss's jam-packed weekend.

In addition to their duet, Sunday's set list had some overlap with Saturday particularly in the StarKid section, but deviated to include more of Criss's solo numbers, much enhanced by the addition of a backing band on Sunday. Joe's is known as a venue frequented by New York artists and the kind of place where newcomers arrive to set the bar and stalwarts set a standard, and Criss's looser set fit in line with that established attitude.

Musically Criss is prone to transforming his songs for each performance, so often his riffs and choices are unfamiliar and unexpected to even his most die-hard fans. Of course, sometimes such fluidity backfires, as when Criss lost track of his lyrics on "Jealousy," a tune off his 2010 EP. Despite jokingly pleading that the crowd restart their cameras for YouTube, the cacophony of shutters and flashes from the avid amateur documentarians in the venue's front rows preserved the moment for the Internet. Watch:

Thanks to the prevalence of smart phones, within seconds of Criss' performances, the visuals were uploaded on sites like Tumblr. And despite the disparity in number and type of fans on Saturday compared to Sunday, the speed at which media traveled was negligible at both events. Broadway's strict camera policies will be a tough break for his rabid fans who flock to see him in "How to Succeed."

This weekend's breakneck debut to his New York stint emphasized that Criss's versatility might be his greatest asset. Placing a concrete category on Criss and his path proves difficult, as he is a deft chameleon from setting to setting, a balance of what his audience demands and what he's interested in projecting, an identity he doesn't let get tangled up in the greater pop culture associations of being "that guy from Glee." Aside from the more Broadway or classic style numbers Saturday, both nights were relatively light on tunes from the Fox show, perhaps a conscious decision as he sets himself apart from his role during the program's brief winter hiatus. If this weekend's distinct variations on Criss as the performer are what he could come up with in barely two days, it's a shame he doesn't have more than a month and a half to spend in the city to push it further.