The online music-streaming service Spotify recently launched in the US, and while it's presently invite-only, it's pretty easy to get signed up if you want to - and you should. There are three tiers: you can listen to music for free, with commercial interruptions every two or three songs; you can pay $5 a month and hear no commercials; or you can pay $10 a month and get commercial-free music that you can also stream to your phone or iPod. And the amount of music available to listen to is pretty astonishing, all things considered.

We thought we'd help get you started with a list of two dozen crucial Roadrunner Records titles that are available right now on Spotify. Here you go!

Chimaira, The Impossibility of Reason
Dream Theater, Systematic Chaos
Dream Theater, Black Clouds & Silver Linings
Fear Factory, Demanufacture
Machine Head, Burn My Eyes
Machine Head, The More Things Change...
Machine Head, The Blackening
Megadeth, Endgame
Nickelback, Silver Side Up
Nickelback, All the Right Reasons
Opeth, Ghost Reveries
Opeth, Watershed
Sepultura, Arise
Sepultura, Roots
Slipknot, Slipknot
Slipknot, Iowa
Slipknot, Vol. 3: The Subliminal Verses
Slipknot, All Hope Is Gone
Theory of a Deadman, Scars & Souvenirs
Theory of a Deadman, The Truth Is...
Trivium, Ascendancy
Trivium, The Crusade
Type O Negative, Bloody Kisses
Type O Negative, October Rust