Common swift that resemble a crescent or a boomerang. Their call is a loud scream in two different tone pitches, the higher of which issues from the female. They often form 'screaming parties' during summer evenings, when 10–20 swifts will gather in flight around their nesting area, calling out and being answered by nesting swifts. Larger "screaming parties" are formed at higher altitudes, especially late in the breeding season. The purpose of these parties is uncertain, but may include ascending to sleep on the wing, while still breeding adults tend to spend the night in the nest. Swifts may nest in former
Screaming (music) in his later songs "Mother" and "Well Well Well" on "John Lennon/Plastic Ono Band". While occasional screaming has been used for effect in heavy metal since the genre's dawn in the late 1960s (with singers such as Robert Plant, Ian Gillan and Rob Halford employing the technique frequently), screaming as a normal method of lyrical delivery first came to prominence in heavy metal as part of the thrash metal explosion of the 1980s. Thrash metal was influenced both by heavy metal and by hardcore punk, the latter of which often incorporated shouted or screamed vocals. The first instance of screaming