Cello is a bowed string instrument with four strings tuned in perfect fifths. It is a member of the violin family of musical instruments, which also includes the violin, viola, and double bass. Old forms of the instrument in the Baroque era are baryton and viol.

The double bass, also called the string bass, upright bass, bass fiddle, bass violin or contrabass, is the largest and lowest-pitched bowed string instrument in the modern symphony orchestra, with strings usually tuned to E1, A1, D2 and G2.

The Viola is just slightly larger then the violin and is usually tuned C,G,D,A. it is part of the violin family between the violin and cello.

The violin or fiddle is a string instrument, usually with four strings tuned in perfect fifths. It is the smallest, highest-pitched member of the violin family of string instruments, which includes the viola, cello, and bass. For there overall size they can be quite loud.