It’s almost enough to un-break your heart, if you’re a Tom Petty and the Heartbreakers fan. The four members of the original/classic lineup of Petty’s longtime band will reunite on stage for the first time in more than 20 years this week, fronted by Chris Stapleton for an opening performance at Wednesday night’s Americana Honors & Awards show in Nashville. That’s happening in conjunction with the announcement of a boxed set due in November that will delve into unreleased material from the group’s earliest days, “Origins 1971-1978.”

The performance on the Americana Awards will have Stapleton backed by Mike Campbell, Benmont Tench, Stan Lynch and Ron Blair. For the finale of the program several hours later, the four OGs will be joined by two latter-day Heartbreakers, Steve Ferrone and Scott Thurston.

Heartbreakers fans don’t have to experience too much FOMO about missing the on-stage reunion: The Americana Awards will be streamed live via video and audio through several outlets, beginning at 7:30 p.m. ET/4:30 PT. It can be seen on NPR Music’s YouTube channel and the Americana Music Association‘s Facebook page; the audio feed can be found on SiriusXM’s Outlaw Country channel and clear-channel WSM-AM as well as Nashville’s FM stations WRLT and WMOT.

An additional appearance by the four original Heartbreakers will take place as part of the AmericanaFest Thursday morning, as Tench, Campbell, Blair and Lynch will take part in a panel, “Tom Pett & the Heartbreakers: 50 Years.” (The panel will not be livestreamed.)

Campbell and Tench were lifers in Petty’s band until the frontman’s 2017 death. Bassist Ron Blair quit the Heartbreakers in 1982, but rejoined 20 years later. Drummer Stan Lynch left the group for good in 1994, seemingly with some musical estrangement from Petty at the time, though he was known to stay in loving contact with other members of the band in subsequent decades. Those four players did subsequently reunite with Petty on stage as a unit once after Lynch’s departure, playing two songs at their Rock and Roll Hall of Fame induction in 2002.

For fans who aren’t in Nashville or can’t tune in, the key news will be the Petty estate and UMe announcing the trove of buried treasure in “Origins 1971-1978,” which comes out to commemorate the 50th anniversary of the band on Nov. 6.

The set is being previewed as of Wednesday’s announcement with a previously unheard Tom Petty and the Heartbreakers track, “Parade of Loons,” from 1978. A music video has also been released for the track, directed by Peter Sluszka and starring Iain Armitage (“Young Sheldon”); watch it below.

The boxed set will come in three configurations — a 5-LP edition, a 4-CD set and what is described as an “uber deluxe edition,” each with a Blu-ray and DVD in addition to the audio content. The vinyl will feature an 88-page “fanzine” with liner notes by veteran rock scribes David Fricke and Bud Scoppa, track-by-track annotations from the original band members and archival photos and memorabilia.

Anyone not able to spring for the boxed set can still look forward to one component being broken out as a single-disc release: “No Sleep Til L.A.” will be available as a stand-alone LP, CD and limited-edition Zoetrope vinyl. The announcement describes it as “a 12-track document of Tom Petty becoming Tom Petty,” exploring the years between the formation of the pre-Heartbreakers band Mudcrutch (which also included Tench and Campbell) and the coming together of Tom Petty and the Heartbreakers as the singer-songwriter’s ultimate band. Seven of the 12 tracks are previously unreleased.

The boxed set also includes remixed and remastered editions of the band’s first two albums, the self-titled and “You’re Gonna Get It,” with extended versions of 11 tracks, including “American Girl” and “Breakdown.”

Rounding the set out are: “Live from the Record Plant 1977,” released in its entirety for the first time; “The Cut Out Bin,” consisting of five “solo” Petty tracks as he explored working with different musicians prior to the Heartbreakers’ lineup solidifying, including an appearance by Leon Russell; and the band’s 1978 performance on the BBC’s “The Old Grey Whistle Test,” with restored audio at the hands of Ryan Ulyate.

The “Old Grey Whistle Test” performance is the set’s DVD component. The Blu-ray disc has all 51 songs in high-res stereo, Atmos and 5.1 immersive mixes.