Back in the bad old days of digital music, the choice was simple: if you wanted free music, you'd either download MP3s from unsigned musicians or you'd break the law. Now, though, the landscape has been transformed. Free music is everywhere online, the sound quality is usually superb and the artists are people you've actually heard of.

Radio stations were quick to move online, and your local radio station almost certainly streams over the web, as do all the BBC ones. Some stations also publish their programmes as podcasts that you can listen to when you're not online. The BBC has a comprehensive collection at www.bbc.co.uk/podcasts, but there's an even wider selection in Apple's iTunes software.

Keep an eye out for podcasts such as Chicago Public Radio's Sound Opinions, which has played host to artists including Radiohead and Arcade Fire, and NPR's All Songs Considered, which has featured guest DJs including Thom Yorke, Lily Allen, Conor Oberst, Ray Davies and Randy Newman.

All songs condisdered

ALL THE SONGS: NPR's All Songs Considered is an excellent music podcast. Apple's iTunes has plenty more available for free

The world of online radio is rather fragmented, with aggregators such as Shoutcast featuring so many stations they're a pain rather than a pleasure to browse, but things should improve early next year for UK users when the BBC and the commercial sector come together in a joint online radio project, aggregating up to 500 UK radio stations in a single portal. The – unnamed as we went to press – project is expected to enter beta testing just before Christmas, and it should be available to the public in early 2010.

Meanwhile, you could always try the radio versions of your favourite magazines: NME, Q and Kerrang have all expanded to become media brands rather than mere print publications, with online radio stations catering specifically for each publication's demographic.

Hang the DJ

Obviously, the problem with radio is that you're not in charge of what's playing, which is why Spotify's on-demand music streaming is so appealing. The free version has retreated behind an invite-only wall – that is, you can't sign up until another user invites you – but a quick trawl through Twitter soon uncovers lots of people with invites to spare.

Don't worry if you can't find an invitation, though, because Spotify isn't the only on-demand music service floating around the internet. Grooveshark, Deezer and PureVolume all have wide selections of music, with the latter focusing on emerging artists.

PureVolume

UNKNOWN MUSIC: PureVolume's emphasis on new artists makes it an excellent way to discover new music

If you prefer the thrill of discovery to the familiarity of your existing record collection, then Last.fm is the place to go. As a free music service it's pretty good, but as a way of discovering new music it's superb: simply enter the names of artists you like and Last.fm suggests others you might not be aware of.

The iLike service operates on a similar principle and is available through www.ilike.com, while Musicovery generates a playlist based on the buttons and sliders you click.