Growing numbers of legal and free music Internet services are appearing offering vast numbers of songs, provided music lovers can stomach the accompanying advertisements.

New York-based QTRAX was the latest to launch a global free and legal ad-funded peer-to-per (P2P) music service Sunday at MIDEM, the world's largest music trade event.

And brands including American toy giant Hasbro are starting to team up with the music world to put music into sometimes unexpected places, including kid's toothbrushes.

The kids "Tooth Tunes" toothbrush, which plays tracks by chart-topping artists, has been a resounding success in the USA and will shortly be launched in Europe and Asia.

QTRAX joins the swelling ranks of services offering an alternative to the huge number of mostly young people who illegally download millions of music tracks every year.

"We will provide a vastly better service than unauthorised sites with superior technology, alluring and vast content, and free music that won't get you arrested," QTRAX president and CEO Allan Klepfisz told reporters.

The arrival of QTRAX and rival services has been welcomed by the world's ailing recording industry, which is struggling to recover from the effects of declining CD sales and rampant illegal music downloads.

EMI, one of the industry's four "majors" (with Universal, Sony-BMG and Warner), recently unveiled massive staff cutbacks.

It has also lost major stars such as former Beatle Paul McCartney, while others such as Robbie Williams have also had publicised differences with the company.

Record companies see the emerging ad-funded online music services as way of wooing back digitally-savvy consumers aged between 13 and 30, which will in turn satisfy their artists and the music rights holders.

QTRAX and the other legal, free P2P music services have the backing of the recording industry for the first time.

They're able to offer legal music for free thanks to a slew of licensing agreements with the major labels as well as the publishers and even some leading independent labels.

Added to that, the new music download services say they can supply music and videos free of the viruses that often plague illegal download sites like LimeWire and provide better audio quality.

"We believe we have the killer application," co-founder of Rebel Digital and QTRAX consultant, Laurence Ford, told AFP, adding that it took QTRAX three years to negotiate copyright with the recording industry.

Many of the other legal, free P2P services are music and music video social networking sites that don't all let fans download music.

Imeem, the fastest growing and fourth largest social networking site in the USA, lets registered users stream songs and music video live from the Internet from artists and labels with whom it has copyright agreements as well as sharing favourite tracks with their friends.

If imeem is any example, the uptake of the new free services could be rapid.

Imeem, which is fully live in the United States and Canada and is growing internationally, has pulled in 20 million users in just 20 months, said chief marketing officer and head of business development Steve Jang. It was gaining between 65,000 and 70,000 new users every day, he added.

As the new service catches on, the whole legal free music scene could explode if online players such as video-sharing giant YouTube and social networking sites such as Bebo and MySpace move in.