Longitudinal wave and seismic P-waves (created by earthquakes and explosions). In longitudinal waves, the displacement of the medium is parallel to the propagation of the wave, and waves can be either straight or round. A wave along the length of a stretched Slinky toy, where the distance between coils increases and decreases, is a good visualization. In the case of longitudinal harmonic sound waves, the frequency and wavelength can be described by the formula where: The quantity "x"/"c" is the time that the wave takes to travel the distance "x". The ordinary frequency ("f") of the wave is given by The wavelength
The Crests group continued well into the 1990s and toured with a five-piece band including Leona Carter on keys. The 1984 John Hughes' teen film "Sixteen Candles" took its title from The Crests' song, which was re-recorded by The Stray Cats for the"Sixteen Candles" soundtrack. In June 1987, for a concert in Peekskill, New York, Maestro, Carter, Torres, and Gough (The Original Crests) reunited as "The Crests", which was organized by Carter. From 1990-2010, Johnny Maestro invited Carter to join him and The Brooklyn Bridge to record with them and to re-record some of their greatest hits. From the late 2000s until