"As time goes by you realise the people you made music with are hard to replace," says Thayil. "We have a very natural working relationship both as musicians and friends. Every time I pick up a guitar to play a part, these guys are part of the process and it feels exactly right and the way we should be doing it." The unconventional rockers, tagged as grunge aspirants because they formed in the '80s, around the time of Green River, Screaming Trees and Mudhoney, were less about slacker rock and more about heavy riffs with odd time signatures. They were metal, yet won a strong alternative music scene following. Soundgarden was one of the first acts to sign to Seattle's Sub Pop, later SST, and then with major label A & M Records, which released Louder Than Love, Badmotorfinger, Superunknown and Down on the Upside. At the peak of their fame they won Grammys for Best Hard Rock Performance for the song Black Hole Sun in 1993 and Best Metal Performance for Spoonman in 1995.

Superunknown in 1994 and Down on the Upside, in 1996, made it to No. 1 on the Australian charts, while Badmotorfinger went double platinum. The band became MTV darlings, proving that, like Nirvana, an indie favourite could climb the commercial ladder. "Soundgarden has always written its own rules," says Thayil. "We aren't a metarock band that write rock songs about rock. We do our own thing and that's what works for us." Soundgarden plan to make a new album for a 2016 release in the next few months. "No studio has been chosen and no songs are written yet," says Thayil. "When we finish these shows in Australia we'll spend a month or more working on it. It's definitely going to happen. "We worked with producer Adam Kasper on our last album and I wouldn't be surprised if we hook up with him again," says Thayil of the Seattle producer who also made Down on the Upside with the band in 1996.

Last month, front man Chris Cornell announced to his 1.83 million Twitter followers that he was back in the studio making a follow-up album to his 2011 Songbook release. During his break from Soundgarden, Cornell started the band Audioslave and showed his fans a prolific songwriting side. He hasreleased four records under his own name, with a fifth on the way. "Chris is very prolific but not all his material is Soundgarden-worthy," says Thayil. "His songs don't always strike us as something we like for the band." So how does a band that split up a decade earlier come back together again? "Sometimes enough water passes under the bridge," says Thayil. "Jamming together feels right and the ideas still come to us, so why not." There's no internal plans in the Soundgarden camp to conquer the charts again or spend as much time touring as in their heyday, but Thayil says being in his mid 50s means he plays in a band because he wants to, not because of any other demands. "We got caught up in the commercial world for a quick moment, but we've been there and done that. We didn't necessarily want to be there, we've slowed down to a level that we are comfortable with," he says.

"We don't write radio hits, you can't dance to our songs and that's why we are Soundgarden." Soundgarden play at Soundwave Festival, Melbourne Showgrounds, on Sunday and Festival Hall on Tuesday, February 24; Sydney's Big Top Luna Park, Milsons Point, on February 26; and Soundwave Festival, Sydney Olympic Park, on February 28 and March 1.