Without music, taking public transport is a hellish experience in which you're surrounded by utter weirdos. Put on headphones, though, and it suddenly becomes a hellish, freak-filled experience with a lovely soundtrack.
Virtually all modern mobiles can play music, but, in many cases, music-playing capability has simply been tacked on as an afterthought. Awkward media players, tinny headphones and poor sound quality mean it's well worth seeking out a handset that's serious about sonics.
Start by checking the phone's feature list. MP3 playback should be a given and it's always a good sign if it can also handle AAC, WMA and OGG files. You'll need space for storage -- plenty of built-in memory is good but an easily accessible card slot is even better since memory cards are dirt cheap these days.
External speakers are useful only for infuriating fellow passengers, and a standard 3.5mm headphone jack is almost essential. If possible, test the phone with a set of decent headphones instead of the rubbish earbuds that are usually supplied.
Stereo Bluetooth (officially A2DP) means you can listen without wires, and, if a phone supports AVRCP, you can even use a compatible Bluetooth headset to pause and skip tracks or adjust the volume without having to delve into your pocket. An FM radio can be surprisingly handy, especially when you want to follow a footy match or get bored with your on-board tunes.
Now for the music player. You're looking for simple, responsive controls that let you browse and select tunes with a minimum of fuss. You should be able to listen to music while using other functions and apps on the phone. Automatically fading out the song when a call comes in and displaying album art are nifty touches, too.
The music-management software is just as important as the music player. Many phones will sync with Windows Media Player but only one company's devices can connect directly to the market-leading iTunes (three guesses which). If you don't want another music manager clogging up your computer, some phones let you simply drag and drop tunes via USB, although you'll sacrifice useful features like playlists and recommendations with this option.
Keep an eye open for other music features, like song identification (where the phone can listen to a tune for a few seconds then spit back the track name and artist), equalisers and the ability to record direct from FM radio.
If you're on an unlimited (or very generous) data tariff, you can also stream music rather than storing tunes on your phone. Spotify has apps for iPhone, Android and Symbian handsets, and Last.fm has both apps and a website accessible from almost any mobile. Streaming sound quality is rarely as good as even the worst MP3s, and it's also prone to stuttering, but you do get access to millions upon millions of tracks.
Finally, who said music phones were all about listening? Today's smart phones are powerful enough to create music, too. There are apps to help you learn the guitar, tune a piano, and even a few -- like uDrummer and Ocarina -- that turn your phone itself into an instrument. You can then lay down sessions using a multi-track recording app or mix and scratch existing songs.
Below, you'll find a round-up of five of the best music phones to suit all budgets, all sound-checked by our very own, golden-eared CNET UK reviewers.