Thomastik-Infeld Alphayue, Violin D String, (Synthetic/Monel), 3/4, Medium. Thomastik-Infeld alphayue strings combine an unbeatable price with Thomastik-Infeld quality which means you no longer have to settle for solid-steel strings to ensure durability. You will love their instant response, supple playability and color-full tone. Alphayue strings also improve the sound of even the most basic student instrument and make music making a treat!