It's become fairly common practice for progressive/technical metal bands to release instrumental versions of albums, which is a great thing for guitarists trying to learn songs or just anyone who loves the music but isn't quite feeling the vocals.
The latest band to ditch the vocals for an instrumental release are TesseracT, who have just released an instrumental version of their debut album, One.
Commented bass player Amos Williams: "TesseracT began as an instrumental project in Acle's filthy cat ridden bedroom, so it has always had quite a strong instrumental focus. That's not to say that we don't enjoy vocals, we love them! But, it is worth noting that with every song we write, we like for it to be able to stand up on its own with or without vocals. We've always had the mind to, about six months after the initial release of One, to then release the instrumental version. It’s something that the fans have always asked us to do, and we felt now was the correct time to do so."
You can pick up the instrumental version of One at iTunes.