Linsan Sterlig, also known as Lin, is a dancer/muscian that plays a violin.
⚠️ SPOILER: From this point, this page reveals spoilers for Allegro.
The novel Allegro starts with Linsan at age six and goes through a twelve year period in a short number of paragraphs. Soon after her eighteenth birthday, her adventures start properly and she remains that age throughout the rest of the novel.
As written, Linsan's talent requires the use of a violin. The forces are shaped primarily by the song, with the various intensities and rhythm used to created different effects.
As Allegro was inspired by Lindsey Sterling's (Wikipedia) music video, Roundtable Rival, Linsan's general appearance and talents reflect Lindsey Sterling's character in the same video.
Please note that while the appearance of the character is inspired by the video, the personality, sexual preferences, and just about everything else is not. Those are entirely made up for the story.