And when that earth-shattering tune hits you, there's no need to wait until home-time to get working on your latest opus. All of the equipment here is portable - even pocket-sized - and ranges from simple recording devices to capture a quick hum to complete studios in miniature. Whether you're after a bit of "giving-it-up-large-style" at 200 beats per minute, or just putting down a few ideas for your four-week opera cycle, these tools should help you to compose yourself.
If you really want to put Abbey Road into your pocket (musicians, mixing desk and all) the Yamaha QY70 Music Sequencer will weigh you down about as much as a Rolf Harris Stylophone. Somewhere inside this box you'll find 519 "voices" (sounds and instruments), 20 drum kits, a range of effects to add such things as reverb, echo and distortion and a brain that can remember up to 32,000 notes of music - the "sequencer". If you need a little stylistic help along the way, a database of over 4,000 professional examples, such as drum patterns, bass lines and chord progressions, can be fitted into your songs. If you have a tune but no chords to go with it, there are also automatic composing features that can help fill in any gaps you have left.
Tunes can be built up part by part, adding a layer at a time; then, rather like a word processor, you can chop them up and rearrange them at will. Pieces can then also be saved on to an ordinary Mac or PC home computer through a connecting lead. You can't exactly do a Shine performance on the tiny keyboard, but then it's pretty hard to compose at a grand piano and get to work at the same time.
Great artists steal, apparently, and if you fancy doing a bit of a Fat Boy Slim and pinching bits of other people's music to mix up for yourself, you need a sampler such as the Yamaha SU10. A sampler essentially listens to a sound that you play - perhaps from a CD or a microphone - remembers it (in digital form) and then allows you to play around by changing its pitch, stretching it to make it last longer, playing it backwards, looping and so on. So, instead of using the sounds of "instruments" that are pre- stored, it uses whatever you feed it to play music with. The higher the sampling "rate", the more faithful the reproduction, and the rate for this unit is 44.1kHz, which is CD quality. So to create a piece with the sound of your mum sneezing, next door's car alarm, and a quick snippet of the James Bond theme (Robbie Williams got away with it), this is the box to use. An optional extra mini-piano keyboard is available to make playing a little more convenient and, like the QY70, it offers a sequencer to remember the patterns you create.
The trusty cassette four-track has been around for years - and may seem a bit geriatric in the face of newer digital devices - but it still offers a cheap way into multi-track recording. Standard cassettes have room for four tracks on the tape, and on an ordinary stereo cassette player two tracks are used at a time to create a stereo recording. When you turn the tape over and play the other side, you hear the recording on the other two tracks, with the tape running in the opposite direction.
A four-track (such as the budget Fostex X14) uses the same ordinary cassettes, but employs all four tracks at once. Plug in a microphone (or use the built-in mic) and you can record your warbling on track one, then listen back to it while recording the pots and pans on track two. That done, you can listen to both those tracks and add your third part, and so on. With the slightly more expensive models, such as the X-24, you can also "bounce down" - once you have filled three tracks, you can take all that music and put it onto track 4 and start the process again. When you have finished, you can plug the machine into an ordinary stereo cassette recorder and make a stereo final "mix" that will play on a standard machine.
If you just want to mumble a quick tune so you don't forget it later on, when you come to develop it into a symphony, there are plenty of "notetaking" devices on the market, from recording Walkmans and dictaphones to high quality recordable Minidiscs. After all, Beethoven got a fair bit of mileage from one tiny idea for the opening of his Fifth Symphony (something like: "da-da-da-dummm").
If sound quality isn't a primary concern, but portability is, the Sony ICD30 offers a notetaker that uses no cassettes or discs, with computer memory to store up to eight minutes of sound in a palm-sized unit. It has two message files which hold up to 99 separate snippets, with facilities for skip through and repeat playing.
Alternatively, if all that mixing, bouncing and taking samples gets a bit too serious, you could invest in a Funrise Double Step-a-tune Electronic floor keyboard. A bit like playing Twister on a piano, it has 16 keys, Rock, Disco, Rap and Dance rhythms, six demo songs and a record/playback function. Great for "Bad" Michael Jackson impressions and it'll double up as a picnic mat when the batteries go flat.
Stockists: Yamaha QY70, pounds 400, Turnkey (0171-419 9999); Yamaha SU10, pounds 200, Turnkey (0171-419 9999); Fostex X14, pounds 120, Turnkey (0171-419 9999); Sony ICD30, around pounds 99, (0990 111999 for nearest Sony dealers); Funrise floor keyboard, pounds 30, Hamleys (0171 494 2000)