Using FlowSongs, Pure Flow or Sensia users can simply press a button on the device when listening to a track to find out its name and artist. They can then push another button to buy the song.
Once the track has been purchased, it can be streamed to a digital radio via an online Lounge account. Many of the tracks are also DRM-free, which means they can be downloaded onto a PC and copied to another device. Tracks are streamed at 128Kbps, while downloaded tracks will be available as 320Kbps files.
FlowSongs has a £2.99 annual subscription, while tracks are priced at either 79p or £1.29.
Initially the service will only be available for users of Pure radio, but 7digital's chief executive, Ben Drury, hopes it will be opened up to other devices in the future.
"A lot of digital music is an impulse purchase. I'd like to see this technology on other devices," he said.
FlowSongs will be initially be made available in the UK as a beta service from August 16. It will be launched in other countries in the coming months.
See also: PURE Evoke 1S Marshall DAB radio