text: On spinet organs, the keyboards are typically at least an octave shorter than is normal for organs, with the upper manual (typically 44 notes, F3–C7 in scientific pitch notation) omitting the bass, and the lower manual (typically F2–C6) omitting the treble. The manuals are usually offset, inviting but not requiring the new organist to dedicate the right hand to the upper manual and the left to the lower, rather than using both hands on a single manual. The stops on the upper manual were often 'voiced' somewhat louder or brighter, and user guides encouraged playing the melody on the upper manual and the harmony on the lower. This seemed designed in part to encourage the pianist, who was accustomed to a single keyboard, to make use of both manuals. Stops on such instruments, relatively limited in number, are frequently named after orchestral instruments that they can, at best, only roughly approximate, and are often brightly colored (even more so than those of theatre organs). The spinet organ's loudspeakers, unlike the original Hammond models of the 1930s and 1940s, are housed within the main instrument (behind the kickboard), which saved even more space, although they produce a sound inferior to that of free-standing speakers; some models had jacks for installing external speakers, if desired.