Cello inexpensive wood that has been blackened or "ebonized" to look like ebony, which is much harder and more expensive. Ebonised parts such as tuning pegs may crack or split, and the black surface of the fingerboard will eventually wear down to reveal the lighter wood underneath. Historically, cello strings had cores made out of catgut, which, despite its name is made from sheep or goat intestines which are dried out. Most modern strings used in the 2010s are wound with metallic materials like aluminum, titanium and chromium. Cellists may mix different types of strings on their instruments. The pitches of
Ukulele of an old wooden cigar box. These instruments usually have four strings; some strings may be paired in courses, giving the instrument a total of six or eight strings (primarily for greater strumming volume.) The strings themselves were originally made of catgut. Modern ukuleles use nylon polymer strings, with many variations in the material, such as fluorocarbon, aluminium (as winding on lower pitched strings), and Nylgut. Instruments with 6 or 8 strings in four courses are often called taropatches, or taropatch ukuleles. They were once common in a concert size, but now the tenor size is more common for six-string