Orchestral instruments

What follows is family by family: what each instrument is, where it sits in the range from top to bottom, and what it is normally asked to do.

The string family

The string family is four instruments plus the harp, and it supplies about two thirds of the players in the orchestra. All four are bowed, all four can be plucked, and all four can hold a note as long as the music needs.

• Violin. The highest and the most numerous. Split into first violins, who take the top line, and second violins, who take an inner line or shadow the firsts an octave or a third below. Brilliant at the top, capable of near silence.
• Viola. A fifth lower than the violin and slightly larger, with a darker, more covered tone. Usually inside the harmony rather than on top of it, and for that reason the least conspicuous instrument on the platform.
• Cello. An octave below the viola. The orchestra's tenor and baritone voice, and the string instrument closest to the human singing range, which is why so many long melodies are given to it. Elgar's Cello Concerto in E minor of 1919 runs four movements and about 30 minutes on that quality alone.
• Double bass. The foundation, sounding an octave below the written note and an octave below the cellos when both play the same line. Six to eight of them give the orchestra its floor.
• Harp. Counted with the strings by convention though it belongs to no section. Forty-seven strings and seven pedals, each pedal retuning one note across the whole instrument. Used for arpeggios, glissandi and colour rather than for melody.

The woodwind family

The woodwind family runs from the piccolo, the highest instrument in the orchestra, down to the contrabassoon, the lowest. Players sit one to a part, so every woodwind player is effectively a soloist. The oboe has one extra duty: it gives the A that the whole orchestra tunes to, because its reed produces the most stable and most penetrating reference pitch.

• Piccolo. Half-size flute, an octave above it, and audible over the entire orchestra at full volume.
• Flute. Agile, clear, weak in its lowest octave and brilliant at the top. Two or three of them in a standard orchestra.
• Oboe. Double reed, narrow and plaintive, and almost impossible to hide. The instrument Karl Jenkins trained on before he became a jazz and rock musician and then a choral composer.
• Cor anglais. The alto oboe, a fifth lower, darker and rounder. Antonin Dvorak gave it the long melody that opens the slow movement of the New World Symphony in 1893, and Sibelius gave it the whole of The Swan of Tuonela.
• Clarinet. The widest dynamic range of any wind instrument, from a whisper to a shriek, and the smoothest legato. Two or three players, usually with instruments in both B flat and A.
• Bass clarinet. An octave below, with a hollow low register that composers use for menace and for calm in about equal measure.
• Bassoon. The tenor and bass of the woodwind, dry and reedy at the bottom, oddly vocal in its upper range.
• Contrabassoon. An octave below the bassoon and the lowest note in the orchestra. Beethoven brought it into the finale of the Fifth Symphony and it has been standard in large scores since.

The brass family

The brass family is four instruments and about a dozen players, and its job is weight, climax and structural signalling. Brass instruments are loud by nature, so composers use them as a reserve: held back, then released. The horn is the connective instrument of the group, able to blend with woodwind on one side and trombones on the other.

• Horn. Four in a standard orchestra, eight in Mahler and Strauss. Wide range, warm in the middle, and the most difficult instrument in the orchestra to play accurately.
• Trumpet. Three players. The brightest and most directional sound available, used for fanfare, for the top of a brass chord and for anything that must cut through.
• Trombone. Three players, two tenors and one bass. A slide rather than valves, so a trombone can slide between notes and can tune a chord exactly. Historically a church instrument, which is why its entry so often sounds solemn.
• Tuba. One player, the bass of the brass section, and rarely a soloist. It supports the trombones rather than leading anything.

Percussion, keyboard and the rest

Percussion is the only family whose membership changes from piece to piece. Timpani are permanent; everything else is added by name. A standard orchestra fields one timpanist and two to four other percussionists, each covering several instruments in the course of one work.

Timpani are tuned drums, normally a set of four, retuned by pedal during the music. The untuned instruments are the bass drum, side drum, cymbals, triangle, tambourine and tam-tam. The tuned ones are the glockenspiel, xylophone, vibraphone and tubular bells. The keyboards, piano, celesta and organ, are engaged as extras rather than employed as members, and the celesta in particular exists almost entirely for one sound, a soft metallic chime made by hammers striking steel plates.

Every standard instrument, and how many of each

Why the list stops where it does

The saxophone, the guitar and the accordion all exist, all have concert repertoire, and none of them is a member of the orchestra. They appear when a composer writes them in, and then a player is engaged for that concert alone. The distinction matters because an orchestra is a payroll as much as a sound: the instruments in the table above are the ones somebody is contracted to bring to work, and everything else is a visitor.

Also in this programme

• The orchestraHow a symphony orchestra is put together
• What is a symphony?What a symphony is, and how it is built
• The sections of an orchestraThe four sections of an orchestra, and what each one is for
• Frederick DeliusThe short orchestral pieces, and the long ones