You have to lower the stakes after an album like Ys, because you can't raise them. Joanna Newsom's follow-up is a lot less formally ambitious: A three-song quickie, with one new song and two old ones, recorded live in the studio with four members of her acoustic touring band. Of course, "less formally ambitious" on Newsom's scale is off the charts on virtually anyone else's. "I was coding a lot of my experience in terms of excess of water," she told Pitchfork last November about the lyrical process that produced Ys, and Ys Street Band-- especially its tremendous new song, "Colleen"-- seems to be conceptual overspill from the album.

"Colleen" is inarguably an excess-of-water song: If I'm reading the handwritten lyric sheet right, it's a sort of Drawing Restraint 9-in-reverse scenario about a woman who's forgotten she used to be a whale, being confronted with the knowledge of her past. (Vivid detail: She's now wearing a corset, which of course would be made of whalebone. A whale in her dream says "What's cinched 'round your waist, Colleen?/ Is that my very own baleen?/ No! Have you forgotten everything?") It may be a way of addressing the kind of Chinese Democracy-style creative block that comes from immersion in making an Important Work: "I tilled and planted, but could not produce/ Not root, nor leaf, nor flower, nor bean; Lord!/ It seemed I overwatered everything."

Too much water again-- and Newsom even line-breaks like a print poet. It's true: She does lead with her lyrics. But she's also an extraordinary and unmistakable tune-maker. Her melodies are Proustian, winding things, so the details of their arrangements and performances signify a lot. Recast without the immense orchestrations of its Ys incarnation, "Cosmia" becomes more intimate, less a framed-and-mounted artifact. And touring seems to have sanded some of the snags off of Newsom's voice; she's singing better here than she has on record before.

The danger of using acoustic instruments is that people may mistake you for a "folk" musician, which Newsom really isn't-- although "Colleen", more than anything else she's written, owes a lot of its lyrical and musical cadences to traditional music of the British Isles. (Remember, "colleen" isn't just a name: Its Irish usage can just mean "girl" or "young woman.") The cadences of her songs and singing have a lineage of which she's well aware; this time, there are faint echoes of Kate Bush and (especially when drummer Neal Morgan harmonizes with her on an excellent remake of The Milk-Eyed Mender's "Clam, Crab, Cockle, Cowrie") Desire-era Bob Dylan, both of whom are similarly well-connected to their own aesthetic roots. But there's nobody else playing Newsom's game right now, and as good as it is that she can produce a varnished marvel like Ys, it's even more heartening to see her moving beyond it this quickly.