John Pearse 650 bluegrass Phosphor Bronze wound

This set is made with phosphor bronze windings for deeper bass. The term "Bluegrass" on this set refers to the gauging. A Bluegrass gauge combines strings 1, 2, and 3 from a light gauge set with strings 4, 5, and 6 from a medium gauge set. The result is a set that sounds much like a medium gauge (more bass, louder volume) but plays more like a light gauge (less tension, easier to bend). And since the word "Bluegrass" just refers to the gauge here, you can still play acoustic rock with this set without fear of being arrested by the string police.