J - Hip hop

Hip hop music (also referred to as rap or rap music) is a style of popular music. It is made up of two main components: rapping (MC'ing) and DJing (audio mixing and scratching); along with breakdancing and graffiti (tagging), these are the four elements of hip hop, a cultural movement which began among African Americans and Latinos in New York City in the early 1970s.

Most typically, hip hop music consists of one or more rappers who chant semi-autobiographic tales, often relating to a fictionalized counterpart, in an intensely rhythmic lyrical form, making abundant use of techniques like assonance, alliteration, and rhyme. The rapper is accompanied by an instrumental track, usually referred to as a "beat" because of the emphasis on rhythm, performed by a DJ, a record producer, or one or more instrumentalists. This beat is often created using a sample of the percussion break of another song, usually a funk, rock, or soul recording. In addition to the beat, other sounds are often sampled, synthesized, or performed. Sometimes, a track can be made up of just the beat by itself, as a showcase of the skills of the DJ or producer.

J - Pop

Pop music, in popular and contemporary parlance, is a subgenre of popular music. Since the term spans many rock, hip hop, rhythm and blues (R&B), country, dance and operatic pop acts, it is reasonable to say that "pop music" is a loosely defined category. The term is also used in a derogatory manner by those who feel that pop acts lack any musically artistic meaning, or in lack of better terminology, represent a "betrayal" away from the traditional sound of either the act themselves or the specific genre to which the act belongs.

J - Rock

Rock is a form of popular music, usually featuring vocals (often with vocal harmony), electric guitars, and a strong back beat; other instruments, such as the saxophone, are common in some styles. The genre of rock is broad, and its boundaries loosely-defined, with distantly related genres such as soul sometimes being included.

A major formative influence was rock and roll, and the terms are sometimes used interchangeably. In the early 1960s rock 'n' roll was seen as being out of fashion, and at the outset of '60s British rock there was an insistence on using the term rock music. With the "British Invasion" this reinvigorated music spread back to the United States, and became a lasting international cultural phenomenon with considerable social impact on the world. Competing claims have credited it with ending wars and spreading peace and tolerance, as well as corrupting the innocent and spreading moral rot. Rock has become popular across the globe, and has evolved into a multitude of highly-varying styles with widespread popularity in most countries today. Overall in terms of album sales, rock is the most popular form of music since the advent of sound recording.

J - Country

Country music, also called country and western music or country-western, is an amalgam of popular musical forms developed in the Southern United States, with roots in traditional folk music, Celtic Music, Blues, Gospel music, and Old-time music.

However, country music is actually a catch-all category that embraces several different genres of music: Nashville sound (the pop-like music very popular in the 1960s); bluegrass, a fast mandolin, banjo and fiddle-based music popularized by Bill Monroe and by the Foggy Mountain Boys; Western which encompasses traditional Western ballads and Hollywood Cowboy Music, Western swing, a sophisticated dance music popularized by Bob Wills; Bakersfield sound (popularized by Buck Owens and Merle Haggard); Outlaw country; Cajun; Zydeco; gospel; oldtime (generally pre-1930 folk music); honky tonk; Appalachian; rockabilly; neotraditional country and jug band.