A haven for the eccentric and experimental, Chicago's Thrill Jockey label is celebrating 15 years with a two-day birthday bash featuring two of its brightest, homegrown stars.

Fiery Furnaces siblings Eleanor and Matthew Friedberger get the party started in characteristically unique fashion. In Eleanor's case, that means matching a pair of ankle-skimming stripy trousers with a patterned shirt and warbling over convoluted 70s rock rhythms bent out of shape by her keyboard-bothering brother. Backed by bass and drums, they hurtle through the tracks from their latest album, Widow City. Every song is so stuffed with ideas it is exhausting, and Eleanor sinks to her knees between bursts of Vicky Pollard-like vocals. There is a cohesiveness of sound between tracks like Navy Nurse and Duplexes of the Dead that has been missing in the past, but their songs still fly off like fireworks, some bursting into beauty, others dying a spluttering death.

Tortoise have spent years perfecting their tender postrock jazz, and it shows. Moving between two drum-kits, two vibraphones, bass, guitar and keyboards, the five-piece are as finely tuned as a Swiss watch. Drumming furiously, John McEntire keeps his chin up and his eyes on the crowd. John Herndon mirrors McEntire's movements, before abandoning his drumkits to lead the crowd in a spot of soul- clapping. Each instrumental opus is a hypnotic blend of sprawling, organic melodies and precise rhythms laced with euphoric electronica. It's All Around You and Salt the Skies are highlights, but everything about Tortoise remains refreshing, from their complex yet pretension-free music, which spans the divide between classical and clubby, to their heartfelt delivery. As Crest's stormy rhythm shifts to a glistening calm, Tortoise leave us in no doubt they are Thrill Jockey's greatest gift.