An interval signal, or tuning signal, is a characteristic sound or musical phrase used in international broadcasting and by some domestic broadcasters. Played before commencement or during breaks in transmission, or (most commonly) between programmes in different languages it serves several purposes:
- It assists a listener to tune his or her radio to the correct frequency for the station.
- It informs other stations that the frequency is in use.
- It serves as a station identifier even if the language used in the subsequent broadcast is not one the listener understands.
The practice began in Europe in the 1920s and 1930s and was carried over into shortwave broadcasts. The use of interval signals has declined with the advent of digital tuning systems, but has not vanished.
Broadcasting services and interval signals
- BBC World Service in English: Bow Bells.
- BBC World Service in English (occasionally): Lillibullero.
- BBC World Service, non-English, non-Europe: three even notes tuned B-B-C.
- BBC World Service, non-English, to Europe: four notes tuned B-B-B-E, spaced to spell out V in morse code.
- China Radio International: chime version of 义勇军进行曲 (Yìyǒngjūn Jìnxíngqǔ, "March of the Volunteers").
- Deutsche Welle Radio: chimes from Beethoven's Fidelio.
- Radio Serbia: national anthem "Bože pravde".
- Radio Australia: chorus of Waltzing Matilda on chimes.
- Radio Berlin International: chimes version of Auferstanden aus Ruinen.
- Radio Canada International: first four notes of O Canada played on a piano.
- Radio France Internationale: electronic-disco, culminating in the last 8 measures of La Marseillaise.
- Radio Japan : さくら さくら (Sakura Sakura, "Cherry Blossoms").
- Radio Habana Cuba: melody of the La Marcha del 26 de Julio ("March of the 26th of July").
- Radio Moscow (former service of the Soviet Union): chimes version of Песня о Родине ("Wide Is My Motherland") and Moscow Nights or Midnight in Moscow.
- Radio Norway International (former international shortwave service of NRK, Norwegian Broadcasting Corporation): ancient folk tune from the Hallingdal region.
- Radio Netherlands: chime version of the Eighty Years' War song Merck toch hoe sterck.
- Radio New Zealand International: the call of a New Zealand Bellbird, a distinctive sounding NZ bird species, repeated every 3 minutes.
- Radio Peking (predecessor of China Radio International): chime version of 东方红 (Dōngfāng Hóng, "The East Is Red").
- Radio Polonia: Etude for Piano No. 12 ("Revolutionary Etude") by Frederic Chopin (historic).
- Radio Prague: melody of Kupředu levá ("Forward, Left").
- Radio RAI International: bird chirping and bells sound.
- Radio Republik Indonesia: Rayuan Pulau Kelapa, composed by Ismail Marzuki.
- Radio RSA: The Voice of South Africa (former service of Apartheid-era South African Broadcasting Corporation): Afrikaner folk tune, "Ver in die Wereld, Kittie" ("Where in the world, Kitty").
- RTÉ Radio 1: O'Donnell Abú ("O'Donnell Forever").
- Radio Slovenia: the European Common Cuckoo chirping, electronically generated.
- Radio Sweden: Ut i vida världen ("Out in the Wide World"), composed by Ralph Lundsten.
- Radio Tirana: melody of With Pickaxe and Rifle.
- Vatican Radio uses the chimes of the clock in St. Peter's Square, Rome, followed by the Papal fanfare.
- Voice of America: Yankee Doodle played by a brass band.
- Voice of Korea: melody of the 김일성장군의 노래 (Kim Ilsŏng Changgunŭi Norae, "Song of General Kim Il-sung").
- Voice of Russia: chime version of "Majestic" chorus from the "Great Gate of Kiev" portion of Mussorgsky's Pictures at an Exhibition.