In surface navigation, a cross sea is a sea state with two wave systems traveling at oblique angles.
 This may occur when water waves from one weather system continue despite a shift in wind.
 Waves generated by the new wind run at an angle to the old, creating a shifting, dangerous pattern.
 Two weather systems that are far from each other may create a cross sea when the waves from the systems meet, usually at a place far from either weather system.
 Until the older waves have dissipated, they create a sea hazard among the most perilous.
 This sea state is fairly common and a larger percentage of ship accidents were found to have occurred in this state.
 Vessels fare better against large waves when perpendicular to the wave.
 In a cross sea, vessels are much more likely to be struck in a dangerous way.
Internal tides are generated as the surface tides move stratified water up and down sloping topography, which produces a wave in the ocean interior.
 So internal tides are internal waves at a tidal frequency.
 The other major source of internal waves is the wind which produces internal waves near the inertial frequency.
 When a small water parcel is displaced from its equilibrium position, it will return either downwards due to gravity or upwards due to buoyancy.
 The water parcel will overshoot its original equilibrium position and this disturbance will set off an internal gravity wave.
 Munk (1981) notes, "Gravity waves in the ocean's interior are as common as waves at the sea surface-perhaps even more so, for no one has ever reported an interior calm."
In physics, a surface wave is a mechanical wave that propagates along the interface between differing media.
 A common example is gravity waves along the surface of liquids, such as ocean waves.
 Gravity waves can also occur within liquids, at the interface between two fluids with different densities.
 Elastic surface waves can travel along the surface of solids, such as "Rayleigh" or "Love" waves.
 Electromagnetic waves can also propagate as "surface waves" in that they can be guided along a refractive index gradient or along an interface between two media having different dielectric constants.
 In radio transmission, a "ground wave" is a guided wave that propagates close to the surface of the Earth.
Optical rogue waves are rare pulses of light analogous to rogue or freak ocean waves.
 The term optical rogue waves was coined to describe rare pulses of broadband light arising during the process of supercontinuum generation—a noise-sensitive nonlinear process in which extremely broadband radiation is generated from a narrowband input waveform—in nonlinear optical fiber.
 In this context, optical rogue waves are characterized by an anomalous surplus in energy at particular wavelengths (e.g., those shifted to the red of the input waveform) and/or an unexpected peak power.
 These anomalous events have been shown to follow heavy-tailed statistics, also known as L-shaped statistics, fat-tailed statistics, or extreme-value statistics.
 These probability distributions are characterized by long tails: large outliers occur rarely, yet much more frequently than expected from Gaussian statistics and intuition.
 Such distributions also describe the probabilities of freak ocean waves and various phenomena in both the man-made and natural worlds.
 Despite their infrequency, rare events wield significant influence in many systems.
 Aside from the statistical similarities, light waves traveling in optical fibers are known to obey the similar mathematics as water waves traveling in the open ocean (the nonlinear Schrödinger equation), supporting the analogy between oceanic rogue waves and their optical counterparts.
 More generally, research has exposed a number of different analogies between extreme events in optics and hydrodynamic systems.
 A key practical difference is that most optical experiments can be done with a table-top apparatus, offer a high degree of experimental control, and allow data to be acquired extremely rapidly.
 Consequently, optical rogue waves are attractive for experimental and theoretical research and have become a highly studied phenomenon.
 The particulars of the analogy between extreme waves in optics and hydrodynamics may vary depending on the context, but the existence of rare events and extreme statistics in wave-related phenomena are common ground.
Circa Waves are an English indie rock band formed in Liverpool in 2013.
 The band consists of frontman Kieran Shudall (vocals, guitar), Sam Rourke (bass), Colin Jones (drums) and Joe Falconer (guitarist).
In meteorology, lee waves are atmospheric stationary waves.
 The most common form is mountain waves, which are atmospheric internal gravity waves.
 These were discovered in 1933 by two German glider pilots, Hans Deutschmann and Wolf Hirth, above the Krkonoše.
Violent Waves is the fourth studio album by the American rock band Circa Survive.
 It was released on August 28, 2012.
 As Circa Survive wanted a record that would capture the band's live sound, where they felt the magic of the band lay, they recorded the album in one week and produced it themselves.
 Violent Waves is also Circa Survive's first and only album released without a record label.
The Gandharvas was a Canadian alternative rock band formed in 1989 in London, Ontario.
Total internal reflection is the phenomenon which occurs when a propagated wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.
 If the refractive index is lower on the other side of the boundary and the incident angle is greater than the critical angle, the wave cannot pass through and is entirely reflected.
 The critical angle is the angle of incidence above which the total internal reflection occurs.
 This is particularly common as an optical phenomenon, where light waves are involved, but it occurs with many types of waves, such as electromagnetic waves in general or sound waves.
Descensus is the fifth studio album by the American rock band Circa Survive, released on November 24, 2014.
 Descensus is Circa Survive's first album released through Sumerian Records, aside from the Deluxe CD/DVD version of the band's previous album, "Violent Waves" which was released on August 28, 2012.
 As with Circa Survive's previous albums, Esao Andrews created the album artwork.

Question: Circa Waves and The Gandharvas, have what in common?
Answer: rock band