LOOSE ROPE FOR CELLO Prelude J1012 Re (D) 3/4 medium tension. Prelude strings are strings made with a solid steel core, unaffected by changes in temperature or humidity, and offer incredible bow response. Prelude strings give us the warmest sound available on solid steel core strings at the best price. Prelude is the teacher's preferred choice for strings for their students due to its unique blend of warm tone, economy, and durability.