The 'Young Guns' tour featuring co-headliners Mammoth WVH and Dirty Honey is officially underway and the Wolfgang Van Halen-led group kicked things off in grand fashion by debuting a previously unreleased song called "I Don't Know At All."

A Feb. 20 stop in Denver, Colorado marked the commencement of the tour, which was originally supposed to launch in early January but was postponed due to the early winter/post-holiday COVID surge. With two of rock's most promising new acts out together, Mammoth WVH sweetened the pot by playing "I Don't Know At All" as a surprise near the mid-section of the set, which was otherwise comprised of tracks solely off the group's self-titled debut that came out last year.

Fan-shot footage of the song performance from the following night (Feb. 21) in Salt Lake City, Utah has emerged and can be viewed below, as well as a video of Mammoth WVH covering the Alice in Chains classic "Them Bones," which was not in the set for the tour kickoff.

The 'Young Guns' tour will continue through April 10 and you can head here to see a list of remaining stops and to purchase tickets.

Mammoth WVH, "I Don't Know At All" — Live Debut on Feb. 21, 2022

Mammoth WVH, "Them Bones" (Alice in Chains cover) — Live on Feb. 21, 2022

Mammoth WVH Set List — Feb. 21, 2022 in Salt Lake City, Utah (via setlist.fm)

01. "Mammoth"
02. "Mr. Ed"
03. "Epiphany"
04. "Horribly Right"
05. "You'll Be the One"
06. "Stone"
07. "I Don't Know At All"
08. "Think It Over"
09. "You're to Blame"
10. "Distance"
11. "Them Bones" (Alice in Chains cover)
12. "Don't Back Down"

11 Bands Leading the Classic Rock Revival

They give nostalgia a modern twist.

The 45 Best Rock + Metal Albums of 2021

These are the 2021 albums we couldn't stop listening to.