The CMJ Music Marathon began yesterday. Lasting through Oct. 25, the acclaimed Music Marathon features hundreds of concerts across Manhattan and Brooklyn, as well as myriad panels hosted by music industry professionals. Here are five acts to see on CMJ’s second day.

Courtney Barnett

This year the Aussie indie artist Courtney Barnett will be one of the headline acts of CMJ at Webster Hall at 8:30 p.m. Barnett can only go up from the critical acclaim she received for her “Double EP: A Sea of Split Peas” this past year. Her drowsy and sardonic storytelling is what sets her apart from the rest of Wednesday’s lineup. Her droning guitars sound similar to those of old Nirvana live sessions. Barnett is able to access the tender, the comical and the relaxed when it comes to her music, providing nothing but good vibes.

Saint Pepsi

Flash back to the ’70s with this groovy producer on Saint Pepsi’s track “Fiona Coyne,” and there is no doubt that you will want to visit his showcase at Mercury Lounge at midnight. Delivering funky electronic beats and gripping guitar melodies, Ryan DeRobertis works solo under the name Saint Pepsi. The young musician released his debut album, “Hit Vibes,” in 2013 and has continued to drop quality tracks along the way, including remixes of Drake and Carly Rae Jepsen. Saint Pepsi will bring a dance party no one will forget.

Tweens

The trash pop rockers who make up Tweens will be performing at Arlene’s Grocery at 5 p.m., ensuring a punk mood. The Cincinnati group released its self-titled debut album this past April. Tweens will welcome you to the world of classic girl punk with jarring guitar leads and relentless energy — think the Ramones replaced with female vocals, or a less ska-inflected No Doubt.

BJ The Chicago Kid

Otherwise known as Bryan James Sledge, the Windy City rapper BJ The Chicago Kid on the rise has worked with Schoolboy Q, Kanye West and Freddie Gibbs, just to name a few. The young wunderkind has released three mixtapes within the last five years, coupled with one studio album named “Pineapple Now-Laters.” BJ The Chicago Kid is expected to release his debut major label album through Motown Records this year. Check out his free set at Le Poisson Rouge at 8 p.m.

Ryn Weaver

After her release of single “OctaHate” went viral, the music world has been ever so curious about the melodic conundrum that is Ryn Weaver. Her fairy pop tunes are whimsical and harmonically beautiful. The 21-year-old has worked with Cashmere Cat, Passion Pit’s Michael Angelakos, Charli XCX and producer Benny Blanco. With her star-studded cast of musical friends and amazing vocal chops, Ryn Weaver will showcase her debut songs at the Bowery Ballroom at 7 p.m.

A version of this article appeared in the Wednesday, Oct. 22 print edition. Email Margaret Farrell at [email protected].