You never know what you're going to hear when a guest stops by 'The Howard Stern Show' -- only that it's going to be honest, off-the-cuff, and no holds barred. That certainly was the case last week when Soundgarden frontman Chris Cornell stopped by the studio to discuss his new album, 'Songbook.'

Stern and Cornell quickly delved into some of the odder stories from Cornell's rock 'n' roll life -- including the time a girlfriend stabbed him through the hand -- and topped things off with heartfelt in-studio performances of John Lennon's 'Imagine' and Led Zeppelin's 'Thank You.'

'Imagine' is one of 16 tracks that appear on 'Songbook,' a live acoustic run-through of new songs and some of the better-known entries from the Cornell catalog (including numbers originally recorded with Soundgarden, Audioslave, and Temple of the Dog). Recorded during Cornell's 2011 spring solo tour, it's his first live album, and offers a trip through his songwriting past while also paying tribute to some of his bigger influences.

To that end, 'Songbook' includes a pair of covers -- 'Imagine' and 'Thank You' -- that Stern persuaded Cornell to perform during his appearance on the show. Cornell recalled hearing Zeppelin at a party and being totally blown away by the experience, but it was Stern and his crew who were blown away when Cornell delivered his take on the classic hits. Hear both performances below.

Soundgarden fans can expect a new album from the reunited band early next year. During a recent visit to the Rolling Stone offices, Cornell promised that the new material picks up where the group left off with their last album, 1996's 'Down on the Upside.'

Listen to Chris Cornell performs 'Imagine' on 'Howard Stern':
Listen to Cornell rocking 'Thank You' on 'Stern':