Many instruments of the orchestra cannot accommodate tuning systems other than even temperament. Although the slide trombone and the stringed instruments can play any pitch in their range, the orchestra as a whole cannot produce the tuning of a barber shop quartet, the ragas of India, or the harmonic changes of an unaccompanied chorus. Neither can it modify tuning systems during the progress of a given performance. This describes only one of many shortcomings of traditional musical instruments.
Most large communities have several orchestras and other musical groups that are populated by volunteers. Often these musicians are retired or of retirement age. These groups are greatly appreciated and bring us much enjoyment. Although their performance flaws are few in number, they reveal patterns.
Wind instruments require the use of facial muscles, lips, teeth, and the tongue to form what is called an embouchure, which often calls for these anatomical features to adjust for the pitch, loudness, and other features of the sound produced by the instrument. This is certainly a challenging aspect of performing music on a wind instrument. Failure to produce or maintain a correct embouchure is responsible for a noticeable fraction of performance flaws.
Elimination of the need for providing air pressure by mouth is a practicable solution to this problem. A guitar-like instrument that provides air pressure with the muscles of the right arm and provides control of a mechanical valve with the fingers of the right hand could provide the power and excitation control for horns or woodwinds. A mirror of this handedness would work as well. This leaves one hand free to select pitches. The creation of such an instrument is well within the publicly-known technology of the 21st century (or the technology of the 19th century, for that matter).
Many innovative keyboards have been designed. Bilinear and Janko are examples.
New instruments inspired by the guitar are very numerous. The are linked by search engines with a search term such as innovative musical instruments.
The instruments of an orchestra are mainly those that produce one note at a time. This is to allow the musician to express only one line of music so that maximum attention to detail can be achieved. Instruments like the guitar and the piano allow chords and multiple simultaneous melodies to be played. These instruments might be called polyphonic.
The term polyphonic is more often used to describe music that is comprised of several harmonizing melodies played simultaneously. This is to be contrasted with chordal accompaniment, where chords accompany a single melody.
Prior to the development of computer software for music composition, composers made extensive use of polyphonic instruments like pianos, harpsichords, and electronic synthesizers to play their compositions, even if those compositions were ultimately intended for multiple instruments or an orchestra. This is still a common practice.
Polyphonic musical instruments make small groups more effective in conveying full harmonies and producing impressive musical performances with fewer musicians. These instruments also help the musician learn harmonic styles and orchestration.
Much can be done to make both polyphonic and single-voice instruments more effective and easier to learn.
Chapter 4 - Music Performed at Home