Capo plays a B note for any capo position at or below the seventh fret), and thus a performer does not need to adjust for or relearn the entire fretboard as they might with retuning. The scale length of the strings of an instrument affects the timbre of the strings, and thus the use of a capo may alter the tone of the instrument. Musicians also use capos to bring a guitar tuned below standard up to standard tuning. Manufacturers sometimes recommend tuning a twelve-string guitar a whole-step or more below standard to offset the additional stress of the additional strings.
Scale length (string instruments) electric basses built in the 1930s by fitting an otherwise normal double bass with electric pickups, and so had a scale length of about 43" (109 cm). In 1951 the Fender Precision Bass shortened this to 34" (86 cm). This is still often regarded as the standard length for a bass guitar. On a modern bass guitar, 30" (76 cm) or less is considered "short" scale, "standard" (also called "long") scale is 34" (86 cm) for a 4-string and 35" (89 cm) for a B-E-A-D-G 5-string, and "extra-long" scale basses of 36" (91 cm) also exist. Quite an uncommon scale