10/21/2013 12:29 EDT | Updated 01/23/2014 06:58 EST

Fiona Apple: Still Crazy (and Amazing) After All These Years

Fiona Apple is fragile, a fact we were reminded of recently when a heckler, apparently concerned about her gaunt appearance, shouted at her to "get healthy -- we want to see you in 10 years," prompting what was reported as an on-stage meltdown.

Apple, who cursed, cried and kicked the woman out in response, dismissed that characterization. "She hurt my feelings," Apple told Pitchfork the following day, adding that, "as a person who performs on-stage, it's good to be emotionally open. If you mess with someone when they are in that state, it's like you're messing with an animal when it's eating."

Indeed, it's not her thinness that resonates the most in this story, but her emotional rawness -- the very same rawness that makes her such a mesmerizing musical presence so many years after she broke onto the pop charts with mid-'90s hit "Criminal."

That song's absence in her current setlist -- a tour that began with that dramatic Portland performance, and took her to Toronto's Queen Elizabeth Theatre late last week before careening to New York, Boston and DC this week, is evidence enough that the singer-songwriter is no '90s nostalgia act.

In fact, The Idler Wheel..., the album she's now touring, topped plenty of year-end lists and the two biggest-sounding songs from her current live show are that 2012 album's "Every Single Night" and "Anything We Want."

But as amazing as her albums are, they pale next to the live-wire emotion she displays in a concert context. When I saw her perform at Austin's SXSW music festival last March, her second show in years, she quietly berated herself on-stage whenever she messed up.

This recent show actually featured a far more together Fiona, albeit one who seems as unstable and unpredictable as ever. Her eyes often seemed crazy, her mannerisms manic and her banter burst forth without filter. But it's this personality trait that bleeds into her songs, making them feel startlingly vital whether they were written in the '90s ("The First Taste") or so new they haven't even been recorded yet ("Tipple," "I Want You To Love Me").

It helps that she's abandoned her original alt-rock influenced sound for one that incorporates jazz, blues, bluegrass and whatever other old-timey genre strikes her fancy, creating a sound that is utterly unique but does bring to mind the work of Tom Waits. Like Waits, her personal eccentricities resound in her lacerating lyrics; whispered, crooned and shouted vocal delivery; and odd, often piano-sprinkled instrumentation, creating an enveloping timelessness that transcends any and all trends.

But where Waits' weirdness can sometimes seem like shtick -- especially if you're familiar with his lounge lizard records -- Apple simply doesn't seem capable of adding artifice to her art.

When she basically collapses onto a giant drum while her rootsy tourmate Blake Mills takes lead -- having both opened for Apple and played in her band in recent years, the virtuosic guitarist Mills does a mix this time as one of three backing musicians who also occasionally intersperses his own songs amongst hers and sings duets like "Tipple" -- it feels like she's just giving herself to the moment, even though research reveals it's happened at other shows. When she contorts her body or frantically runs her hands through her hair, that's Apple not burying the impulses the rest of us do.

At another point she sighed, and the followed it with a growl -- and then followed that with some self-psychoanalysis, describing it as "the sound of weakness and the sound of fake strength." Even when her instinct is to cover up how she's feeling, she can't help but reveal all.

This is the case even when she writes a song for a Steve Carell movie, too. "Dull Tool," composed for the 2012 film "This Is 40," unexpectedly wound up as the concert highlight, in part because it felt like such a powerful rebuke to the "get healthy" controversy.

The song begins as whispered critique -- "you don't kiss when you kiss / you don't fuck when you fuck / you don't say what you mean / you don't talk loud enough" -- but soon surges in intensity until Apple is practically screaming seemingly loud enough for even that heckler to hear.

Elsewhere in the song, she croons, "you forgot that glorious feeling that you get when you get the truth," a drippingly ironic statement in an intensely honest performance, and career, during which Apple has never let us forget her gloriousness.

Fiona Apple