One way to reach her, from Lletya, is to exit the Lletya gates, pass the Lletya strange trees to the west, pass the tripwire to the west, and go through the dense forest just west of that. Another way to reach her, from the Tirannwn lodestone, travel north-west, then pass the stick trap to the east. You will reach the central clearing, which contains a Hunter training area as well as the elf musician.
She sits on a tree stump and plays an ocarina, a likely reference to the Legend of Zelda: Ocarina of Time, where the elf-like Kokiri, Saria, sits on a tree stump in the Lost Woods while playing her ocarina.
When asked about who she is, after describing herself as a musician, she praises the curative effects of music, and says that this information was given to her by "a travelling medical practitioner, selling oil extracted from snakes." This is a reference to a "snake oil salesman," an expression for one who deceives the public by selling false cures. In this case, however, what this salesman is said to have told her is genuine, as indeed you actually do gain run energy and life points at a faster rate when resting to music, and thus that the elf musician has not been deceived. The elf musician, when asked, expresses clearly that music is not a true cure all, and cannot aid with such ailments as "[p]oison, lack of faith, and dismembered limbs."
Elven Resting Song
Song that plays when you rest before Elf Musician.