Mobile tones bbrriinngg! bbrriinngg! a small fortune for web composer

Jean Hasse expects her first royalty cheque any day now. Hundreds of people play her music. Thousands hear it – in shops, restaurants, trains, streets. But you probably couldn't hum any of her work. Jean is the first professional musician to compose ring tones for mobile phones

Five of the dozens of ringtones she has written have got into the "top 10 most popular downloads" at the website iobox.com, where people can download files that will make their phone ring differently when a call comes in. And every time someone buys and downloads one of the files she created, she gets a cut.

It might be a small cut, hundredths of a penny per download. But ringtones downloads are big business, reckoned to be worth more than £1m a day as people pay between £1 and £1.50 per tone to stand out from the crowd.

Ms Hasse's ambitions go beyond simply making money. She nurtures a dream that one day she might write a piece for a collection of mobile phones. "I've written pieces for 'as many flutes as possible'," she said. "And I have thought about writing a piece for between eight and 10 mobiles, each playing a different ring tone at a different time...."

Anyone sick of hearing the tinny sounds of most mobiles might think that there are too many ring tones already. But American-born Ms Hasse, 42, who lives in Deal, Kent, realised that with her musical training she could explore an entirely new instrument, which would in theory be able to create an utterly new set of sounds.

She said: "I didn't even own a mobile, but I realised that you could write music for them. And I happen to be very good at writing the sort of short pieces that you need: about five to 10 seconds long, 50 to 55 notes or rests, and sounding as though they wrap around from the end to the beginning."

She bought a mobile to listen to the ringtones available for it, and started trying her hand in January, when she contacted iobox. The firm hired her at once to write "unique tones" for the site. On Valentine's Day, iobox.com ran a special promotion of her tones, with names such as "Loving You", "Love You" and "Secret Song". They were a huge hit, and she kept writing.

She writes her tones on a piano, and then transfers the piece to a computer-file format known as MIDI, which specifies both tone and timing for notes. That file is sent to iobox, which converts it into a ringtone. Presently those only work on Nokia mobiles, though Ms Hasse is speaking to Ericsson. But like every other musical instrument, mobile phones have their peculiarities lying in wait for would-be composers. "They actually play at a higher pitch than you write," Ms Hasse says. "And the tempo ... something very strange happens to the tempo."