It’s the second year of Rock the Garden being a two-day event. It’s also the second year that tickets haven’t sold out in advance. Co-presented by Walker Art Center and 89.3 the Current to fuel their membership numbers, the event is thus no longer a members-only affair.

SATURDAY

A couple of the Current’s stable artists since Day 1 are heading up opening day of RTG 2015 — Belle & Sebastian and Conor Oberst — but the biggest buzz seems to be for newcomer Courtney Barnett. The whimsical and bookwormy Scottish indie-pop vets of B&S (8:45 p.m.) haven’t been to town in nine years and have a lively new album to tout. After years of excelling at angsty and/or mopey records with Bright Eyes and other bands, Omaha’s folky scene maker Oberst (7:15) also lightened up with his latest solo effort. Australia’s lyrically rambling slacker-rocker Barnett (5:45) made a splash last year with her woozy single “Avant Gardener” and now has one of this year’s most acclaimed rock albums, offering traces of Lou Reed and Nirvana with her own unique cleverness.

Poppy Brooklyn art-rock quintet Lucius (4:30), led by vocally and visually harmonious singers Jess Wolfe and Holly Laessig, have actually played more shows locally than local openers the Stand4rd, the electro-rap/R&B quartet starring YouTube-famous teen luva-boy Spooky Black and Kanye’s “All Day” guest rapper Allan Kingdom.

SUNDAY

Headliners Modest Mouse (8:45 p.m.) are the biggest name and the biggest gamble this year. Isaac Brock’s idiosyncratic Washington/Oregon area rock band has been spotty in concert going back to their “Float On” hitmaking days a decade ago, but their first album in eight years suggests they’re on solid ground again. They head up one of the most eclectic days ever for RTG, most notably with the inclusion of Afrobeat music heir Seun Kuti and his band Egypt 80 (5:45), whose dance-filled set should soften the ground for the Babes in Toyland mosh pit (7:15).

Another son of a late music legend, Sean Lennon, impressed an Entry crowd last year with his psychedelic new band, Ghost of a Saber Tooth Tiger (3:45). And the lone rootsy/Americana act this year, Oklahoma’s vintage “North Side Girl” singer JD McPherson (4:30) leapt past any sophomore-slump talk with his surprisingly hard-blasting new album.

CHRIS RIEMENSCHNEIDER