Question: What genre does The Boxing Mirror and Heart have in common?
Context: In astronomy, a mirror support cell - more commonly mirror cell - is a component of a reflecting telescope that supports the mirror in place to hold optical alignment, allow collimation adjustment, and protect it from falling out.  The common usage of the word denotes the cell that holds the primary mirror (M1), however technically it could also be used to denote the support assembly (usually called a "spider" or "strut") for the secondary mirror (M2) or other mirrors. A curved mirror is a mirror with a curved reflecting surface.  The surface may be either "convex" (bulging outward) or "concave" (bulging inward).  Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices.  The most common non-spherical type are parabolic reflectors, found in optical devices such as reflecting telescopes that need to image distant objects, since spherical mirror systems, like spherical lenses, suffer from spherical aberration.  One advantage that mirror optics have over lens optics is that mirrors do not introduce chromatic aberration. A dielectric mirror, also known as a Bragg mirror, is a type of mirror composed of multiple thin layers of dielectric material, typically deposited on a substrate of glass or some other optical material.  By careful choice of the type and thickness of the dielectric layers, one can design an optical coating with specified reflectivity at different wavelengths of light.  Dielectric mirrors are also used to produce ultra-high reflectivity mirrors: values of 99.999% or better over a narrow range of wavelengths can be produced using special techniques.  Alternatively, they can be made to reflect a broad spectrum of light, such as the entire visible range or the spectrum of the Ti-sapphire laser.  Mirrors of this type are very common in optics experiments, due to improved techniques that allow inexpensive manufacture of high-quality mirrors.  Examples of their applications include laser cavity end mirrors, hot and cold mirrors, thin-film beamsplitters, and the coatings on modern mirrorshades. Integrated Science Instrument Module (ISIM) is a component of the James Webb Space Telescope, a large international infrared space telescope planned for launch in 2018.  ISIM is the heart of the JWST, and holds the main science payload which includes four science instruments and the fine guidance sensor.  ISIM is the spacecraft chassis and instruments that take the light from the main mirror and convert that into the science data that is then sent back to Earth.  The other two major sections of the JWST are the Optical Telescope Element (OTE) (mirror and their structure) and the Spacecraft Element (SE), which includes the Spacecraft Bus and Sunshield.  ISIM has a mass of 1.4 metric tons (tonnes) (1.54 US tons).  The infrared camera instrument integrated with ISIM passed its thermal tests in early 2016.  ISIM underwent intense thermal cold testing in late 2015 to early 2016.  NIRcam is extremely important to JWST, because it's not only a sensitive infrared camera, but it is also used to adjust the alignment of the main mirror segments.  The tests were very positive because NIRcam showed was very stable through vibration and thermal testing.  NIRcam was installed into ISIM in March 2014, and then underwent integration and testing after that, as the telescope is readied for its 2018 launch.  ISIM is about 23% of the overall mass of JWST, which equates to an ISIM mass of 1400 kg (3086 lb). Genre painting, also called genre scene or petit genre, depicts aspects of everyday life by portraying ordinary people engaged in common activities.  One common definition of a genre scene is that it shows figures to whom no identity can be attached either individually or collectively—thus distinguishing "petit genre" from history paintings (also called "grand genre") and portraits.  A work would often be considered as a genre work even if it could be shown that the artist had used a known person—a member of his family, say—as a model.  In this case it would depend on whether the work was likely to have been intended by the artist to be perceived as a portrait—sometimes a subjective question.  The depictions can be realistic, imagined, or romanticized by the artist.  Because of their familiar and frequently sentimental subject matter, genre paintings have often proven popular with the bourgeoisie, or middle class. Heart is an American rock band that first found success in Canada and later in the United States and worldwide.  Over the group's four-decade history, it has had three primary lineups, with the constant center of the group since 1973 being sisters Ann Wilson (lead singer) and Nancy Wilson (guitarist).  Heart rose to fame in the mid-1970s with music influenced by hard rock and heavy metal, as well as folk music.  Their popularity declined in the early 1980s, but the band enjoyed a comeback starting in 1985 and experienced even greater success with album-oriented rock hits and hard-rock ballads into the 1990s. A mouth mirror or dentist's mirror is an instrument used in dentistry.  The head of the mirror is usually round, and the most common sizes used are the No. 4 Ø (18 mm) and No. 5 (Ø 20 mm).  A No. 2 is sometimes used when a smaller mirror is needed, such as when working on back teeth with a dental dam in place.  The mouth mirror has a wide range of uses.  Three of its most important functions are allowing indirect vision by the dentist, reflecting light onto desired surfaces, and retraction of soft tissues.  There exists 2 different norms of the thread that are not compatible to each other.  The US norm have a taper thread and is mostly used in the United States, Canada, Spain and South Korea. Liquid mirror telescopes are telescopes with mirrors made with a reflective liquid.  The most common liquid used is mercury, but other liquids will work as well (for example, low melting alloys of gallium).  The liquid and its container are rotated at a constant speed around a vertical axis, which causes the surface of the liquid to assume a paraboloidal shape, suitable for use as the primary mirror of a reflecting telescope.  The rotating liquid assumes the paraboloidal shape regardless of the container's shape.  To reduce the amount of liquid metal needed, and thus weight, a rotating mercury mirror uses a container that is as close to the necessary parabolic shape as possible.  Liquid mirrors can be a low cost alternative to conventional large telescopes. Compared to a solid glass mirror that must be cast, ground, and polished, a rotating liquid metal mirror is much less expensive to manufacture. The Boxing Mirror is a 2006 album by Alejandro Escovedo.  released through Back Porch Records.  Produced by John Cale of The Velvet Underground, the album finds Escovedo delving into the worlds of avant-rock and post-punk; and its darker sound has only shades of roots rock/Americana music in comparison with most Escovedo's alt-country records.  Legendary bassist, Mark Andes (Spirit, Jo Jo Gunne, Firefall, Heart, Eliza Gilkyson, Jon Dee Graham, Ian McLagan), plays and sings back-up vocals. Mirror writing is formed by writing in the direction that is the reverse of the natural way for a given language, such that the result is the mirror image of normal writing: it appears normal when it is reflected in a mirror.  It is sometimes used as an extremely primitive form of cipher.  A common modern usage of mirror writing can be found on the front of ambulances, where the word "AMBULANCE" is often written in very large mirrored text, so that drivers see the word the right way around in their rear-view mirror.
Answer: rock