A trill can refer to two main concepts, one in music and one in phonetics:
In Music
A trill is a musical ornament consisting of a rapid alternation between two adjacent notes, usually a semitone or whole tone apart. This quick back-and- forth between the principal note and the note above it adds rhythmic, melodic, and harmonic interest to the music. Trills are often notated with the letters "tr" above the note, sometimes accompanied by a wavy line. The speed and number of alternations can vary depending on the tempo and style, and trills may start on the main note or the auxiliary note above it. They are used to embellish melodies and create expressive effects in compositions
In Phonetics
A trill is a consonantal sound produced by vibrations between an active articulator (like the tongue or lips) and a passive articulator in the vocal tract. For example, the rolled "r" sound in Spanish (as in "perro") is an alveolar trill, where the tongue rapidly vibrates against the alveolar ridge. Trills can also occur with other articulators such as the uvula or lips, and are characterized by multiple rapid contacts caused by the airstream
Additional Meaning
The term "trill" can also describe a bird call consisting of a series of quickly repeated high notes, producing a fluttering sound
. In summary, a trill is either a rapid musical ornamentation between two notes or a speech sound involving rapid vibrations of an articulator, and it can also refer to a bird's repeated high-pitched sound.
