Written by Mashable Team

Online music has always been popular, and now social networks, peer recommendations and personalized radio stations are helping fans find bands faster than ever before. Here are more than 90 sites for musicians, fans, and everyone who enjoys music.

Internet Radio

Last.FM – one of the most popular music communities around, with personalized radio stations, a stunning array of social networking features, RSS support and lots more.
Slacker – personalized Internet radio which offers a desktop version of the application and a hardware portable music player. Available only in the United States.
ShoutCast – A large directory of Internet radio stations, categorized by genre. Streams work in Winamp.
Live365 – A directory of web-based Internet radio stations – expect popups.
Yahoo! Music – listen to Internet radio and watch music videos on Yahoo’s music portal.
AOL Music – AOL’s take on internet radio. Offers music from XM as well.
Pandora – a very popular Internet radio/community which brings you new music based on stuff you like. Works only in the US & Canada at the moment.
Yottamusic – a huge music library boasting over 3.4 million songs, accessible from your web browser.

Music Discovery Tools

MusicMesh – browse through artists based on their similarities; find tracklists and reviews for albums.
Blogmusik – browse through top lists and listen to popular artists for free.
Musicovery – discover new music with this cool take on Internet radio.

Social Networks

See also: 12 of the Best Music Social Networks

iLike – a community that lets you discover new music based on you and your friends’ tastes.
PureVolume – a “MySpace for music”, albeit with a classier design.
ProjectPlaylist – popular site for sharing playlists and posting them to other social networks.
Imeem – another playlist-sharing community for artists and fans that also supports embedding of tracks on other social sites and blogs.
MP3.com – the famous music site is now a social network similar to MySpace Music.
iJigg – a place for indie bands and artists to post their music, which the users can download for free.
MOG – a place to share your music and video library and exchange thoughts on music with others.
Fuzz – discover new music; artists can sell their music, but there are also free songs to be found on the site.
eListeningPost – convert your tracks into preview files, then sell them and keep 94% of the profits.
ProjectOpus – Music community for indie bands, complete with widgets to post on MySpace and blogs.
Rapspace.tv – social networking for rap and hiphop.
Musocity – a music community with profiles for fans, artists, retailers and music venues.
Haystack – social networking, playlist sharing and band profiles.
Bandbuzz – find and rate music playlists in a Digg-like interface.
Midomi – find songs by humming or singing the tune. Then explore profile pages and network with others.
Buzznet – large pop culture community with news, videos, photos and member profiles.
JukeboxAlive – Upload music and share tracks with friends. Bands can sell their CDs, write a blog and post events to a calendar.
MusicHawk – track bands and see band-related news and reviews, as well as information on gigs and new releases.
ReverbNation – social network connecting bands, fans and venues.
MusicNation – find new music, watch music videos; if you’re an indie/unsigned artist, join for a chance to get exposure or even a record contract.
Grooveshark – an online service that rewards you for sharing, reviewing, and discovering new music (currently in private testing – enter you email address on the homepage to be notified of the launch).
Dopetracks – upload and share your tracks and beats, and record music online.
Funk Player – a music sharing community where authors can upload songs, while everyone can bookmark, select, listen and comment on them.
FIQL – social playlist sharing.
Soundflavor – create playlists and share them with other users; meet people with similar taste and discover new music.
FineTune – pick an artist and receive a custom playlist featuring music by that artists and other related artists.
MusicMobs – browse through playlists and create your own in a simple interface.

Music Sharing Applications and Widgets

uPlayMe – a downloadable application that lets you meet people with similar music tastes.
DotTunes – share your iTunes collection with friends through your web browser.
Audiozue – A Mac OSX application that posts your recently-played iTunes tracks to your MySpace page or blog.
Sonific – a music network where you can store the music you hold the rights to, and syndicate it to other sites with SongSpot widgets.
Mediamaster – upload your entire music collection and access it from anywhere in the world. You can also publish this music via widgets to any website.
BooMP3 – upload and share your MP3s; unlimited hosting.
Goombah – an application that scans your iTunes library and connects you with like minded users.
Maestro – upload your entire music library and access it from anywhere.

Music Marketplaces

iTunes – Apple’s overwhelmingly popular music download store is a service that requires little in the way of introduction.
Amie Street – music market where music starts with free price, and the price increases as a track becomes more popular (the price never goes above 1 dollar).
Emusic – one of the most successful “indie” music stores, with over 100 million DRM-free tracks sold.
Bleep – high-quality MP3s with prices that are a bit high, but offering a great assortment of quality music.
MP3 Tunes – an online music store offering 30,000 albums and some 360,000 songs in its catalog.
Amazon – a soon-to-come music store which should have a huge assortment of music from big and indie labels alike.
PayPlay.FM – choose between over 1.4 million indie music tracks, and buy them in either MP3 or WMA format.
Beatport – a Flash-based music store with an embeddable player.
Audio Lunchbox – choose between 2 million DRM-free songs in MP3 or OGG format.
Indiepad – buy music from indie artists; if you’re an artist, sell music to people directly on the site.
Indistr – another audio marketplace that connects indie artists with the listeners.
Mtraks – an indie music marketplace with a very interesting and quite strong music collection in store.
MagnaTune – here you’ll find an assortment of music from various genres, ranging from electronica, rock and chillout to metal & punk.
Jamendo – an online music repository offering thousands of albums for free while still protecting the artists’ intellectual rights.
Musicane – buy and sell audio, video and ringtones.
Musiclovr – music search, recommendations and a store. Purchases are made via Amazon and iTunes.
MySpace Music / Snocap – through Snocap’s embedded music stores, bands on MySpace sell tunes to the social network’s huge audience. Bands can also sign up for Snocap independently and sell music elsewhere.

Jamming

Ejamming – jam with other musicians and record music online.
Kompoz – compose music with other musicians. Record a track, then invite other musicians to add their own instruments.
Jamnow – a musical collaboration site where you can jam with other musicians. Jam sessions can be broadcast live.
Indaba – listen to completed music or works in progress and give your feedback; join in the music-making sessions or start your own.
JamJunky – have a song that’s not quite finished yet? Or, better yet, have a dozen? Organize them with JamJunky.

Karaoke

Singshot – the “YouTube of Karaoke”: record yourself singing along to popular music and listen to others doing the same.
kSolo – sing along to backing tracks, and rate the recordings of others.

Remixing

Jamglue – remix your music online and listen to other users’ mixes.
Splice – upload samples, remix them and post them for others to hear.
YourSpins – mix your own version of your favorite track, share it and post it to your blog or MySpace page.

Mobile Music Services

Flotones – a mobile social network which allows indie bands and artists to sell their content for use on mobiles.
Entertonement – a large directory of ringtones, with top lists and categorization for easier browsing.
Mercora – a social radio network that enables you to search and listen to over 3.5 million songs; offers an application for listening to music on your smartphone.

Music Charts

Billboard – home of the Billboard charts, with music videos and reviews.
MTV’s music charts – MTV charts and videos. Videos playable only in the US.
ChartU – a “Digg for music”: vote on tracks to boost them up the chart.

Artist Databases

Allmusic – probably the most comprehensive music database on the Internet. If your favorite artists aren’t there, well, then you’re listening to some pretty unknown artists.
Pandora Backstage – artist profiles and discographies from the personalized streaming service. You can create a custom radio station straight from an artist’s page.

Lyric Databases

AbsoluteLyrics – Lyrics for all major artists.
Hot Lyrics – huge alphabetized lyrics database. Hard to navigate, but lots of content.

Music Search Engines

Qloud – Music search meets social networking. Currently back in private testing once, but Mashable has a review here. The service that launches next may be substantially different, however.
FindSounds – a search engine for sound effects and music instrument samples.
Musipedia – find and listen to songs based on keywords you provide.

Audio Conversion Tools

Zamzar – converts all sorts of file formats, including several audio formats.
Media Convert – a media converter with a huge amount of options.
MediaConverter – a media converter that can be slow and needs polishing, but can sometimes yield really good results.

Miscellaneous Music and Audio Tools

Bluegrind – converts text to audio.
BePopular – find gigs in UK and Ireland and get your tickets.
Getabuz – create voicemail and audio e-cards online.
iden.tify.us – can’t figure out where a certain melody comes from? Identify it with the help of this service.
Houndbite – share funny audio clips from your life with other users, with the possibility to earn prizes.

What did we miss? Extend the list in the comments.