Who pays the songwriter and for what when you ask your mobile operator to send you back a track – a ringback? US publishing collecting society BMI has launched a lawsuit against T-Mobile for payment for their ringback tones service – but there seems to be some confusion over whether the payment should be mechanical (as a single download) or a performance royalty (as a stream). This is not the first time the courts have been troubled on mobile music; ASCAP recently lost a legal attempt to get a royalty from traditional ringtone sales. They argued that while a mechanical royalty was paid when the ring-tone was first downloaded, they should also get a fee because there was a “public performance” of the track every time a user’s phone went off. The US court hearing the case did not concur. BMI told the Register that “despite extensive BMI efforts spanning several years, T-Mobile has not signed a licence agreement”.