Trynl Record

A Trynl Record, often simply referred to as Trynl, is a form of Troll music storage format, comparable to the Vinyl records of Earth.

Source
Trynl Records are said to have been made when one of the trolls ordered to clean up the large mess of black blood left behind after Mindfang killed His Honorable Tyranny thought of the idea of giving a use to the blood. He would later invent the process of heat-pressing the blood to solidify it into disks, onto which grooves could be cut for the music to be playable on a Trynl Groove Tracer (commonly called a Record Player). It is known that after the black blood was used up, substitutes were created, which was said to noticeably change the quality of music. Original black blood copies of Trynl are sought after by collectors.

Trivia
The name is a portmanteau of the words 'vinyl' and 'tyranny'.