diapason

He strove for the diapason, the great song that should embrace in itself a whole epoch, a complete era, the voice of an entire people, wherein all people should be included--they and their legends, their folk lore, their fightings, their loves and their lusts, their blunt, grim humour, their stoicism under stress, their adventures, their treasures found in a day and gambled in a night, their direct, crude speech, their generosity and cruelty, their heroism and bestiality, their religion and profanity, their self-sacrifice and obscenity--a true and fearless setting forth of a passing phase of history, un-compromising, sincere; each group in its proper environment; the valley, the plain, and the mountain; the ranch, the range, and the mine--all this, all the traits and types of every community from the Dakotas to the Mexicos, from Winnipeg to Guadalupe, gathered together, swept together, welded and riven together in one single, mighty song, the Song of the West.

- Frank Norris, The Octopus, ch. 1

Musically speaking, the air flowed, as its compression sometimes, from an organ-pipe, flute or diapason.

- Louis Zukofsky, Thanks to the Dictionary

the range of an instrument or voice, an octave, an "outpouring of sound"

A black sheep boy grows horns
Breathing smoke through his microphone
The airwaves stretch and they groan, bleeding, birthing his black diapason

-Okkervil River