LP Underground 15 (LPU 15), is the fifteenth LPU installment, and spans nearly the entire career of Linkin Park. Of which the LPUs contain unreleased demo tracks made by the band.
It will contain the first six music tracks for the year are available on CD. The next 6 tracks will be available to you as free downloads every other month and will complete this collection, making a total 12 tracks for the album.
The first six tracks were released on 21st November, 2015, with each new track being released bi-monthly (every 2 months), leaving the album incomplete at the time of writing, with the final track expected by mid October 2016.