Bass guitar the 3rd, 5th, 7th, 9th fret and 12th fret (the 12th fret being the octave of the open string) and on the octave-up equivalents of the 3rd fret and as many additional positions as an instrument has frets for. Typically, one marker is on the 3rd, 5th, 7th and 9th fret positions and two markers on the 12th fret. The long scale necks on Leo Fender's basses—with a scale length (distance between nut and bridge) of — set the standard for electric basses, although "short scale" instruments, such as the Höfner 500/1 "violin bass" played by Paul McCartney, and the
String vibration or, perhaps more easily, by adjusting the machine heads, to obtain the same, or a multiple, of the AC frequency to achieve the same effect. For example, in the case of a guitar, the 6th (lowest pitched) string pressed to the third fret gives a G at 97.999 Hz. A slight adjustment can alter it to 100 Hz, exactly one octave above the alternating current frequency in Europe and most countries in Africa and Asia, 50 Hz. In most countries of the Americas—where the AC frequency is 60 Hz—altering A# on the fifth string, first fret from 116.54 Hz to