MY MORNING JACKET On its fourth album, “Z” (released today), My Morning Jacket has traded its hair-flowin’, beer-drinkin’ vibe for an experimental prog rock sound.

“Wordless Chorus,” the opening track, begins with a syncopated synth beat and Jim James’s vocals, a far cry from the usual country and rock-inflected introductions. The song opens up during the chorus in the band’s traditional way, with soaring choral vocals carrying the tune to the next verse, but the sound remains timid without the strong guitar backbone that used to be an MMJ trademark.

At times, the harmonies on “Z” take on a Monty Python-esque quality, but the album redeems itself somewhat with the ballad “Knot Comes Loose,” a song with a lovely piano riff reminiscent of Maurice Ravel’s “Le Tombeau de Couperin” and a simple plaintive chorus of “I will remember you.” “Z” may not be a barnstorming album like “It Still Moves,” but it retains an essence of MMJ’s pure country-rock spirit.

My Morning Jacket’s music is much less contained on stage, and the band is well-known for presenting rougher, longer versions of its songs, allowing for such luxuries as drum and guitar solos that otherwise would not work on an album. Tonight at Knitting Factory (74 Leonard Street, 212-219-3132).

SUSIE IBARRA Percussionist Susie Ibarra made her name on New York’s improv-jazz scene, but she’s not against collaboration with the likes of Hoboken indie rockers Yo La Tengo. On Thursday night she plays with Okkyung Lee (cello) and Min Xiao-Fen (pipa, voice); followed by a set with another percussionist, the hand-drum master Adam Rudolph. The Stone (NW corner of Avenue C and 2nd Street,www.thestonenyc.com).

JUANA MOLINA A former comedienne, Juana Molina is one of the most interesting new musicians from South America. Her distinctly soft vocals and sparse instrumentation (guitar, shakers) play to a throbbing collage of sounds. The density of sound may vary, but she maintains a warm sumptuousness throughout.

Thursday at Joe’s Pub (425 Lafayette Street, 212-254-1263).

MAGIK MARKERS An innovative hardcore-noise band, Magik Markers got the attention of noise guru Thurston Moore, resulting in a tour with Sonic Youth in 2004. This year they released their first non-CDR album, “I Trust My Guitar, etc.” (Apostasy). Since that already sold out, you’ll have to see them Saturday night at Tonic (107 Norfolk, 212-358-7501).

Also, Liz Phair plays tonight at Irving Plaza (17 Irving Place, 212-777-6800); Death Cab for Cutie tomorrow at Hammerstein Ballroom (311 W. 34th Street, 212-564-4882); Devendra Banhart on Thursday at Webster Hall (125 E. 11th Street, 212-353-1600); Stars on Thursday at Hammerstein; James McMurtry on Saturday and Sunday at Mercury Lounge (217 E. Houston Street, 212-260-4700).