What is goth?
Goth is an alternative subculture; it is both a style of music and a fashion, like Punk. People who listen to the music don't necessarily dress in the style, and people who look like Goths don't necessarily like the music either - a lot of metal fans have adopted the goth look, making for a great deal of confusion.
However, on the rare occasion that someone looks like a goth and likes goth music, chances are they're actually a goth.
Especially if they deny it.
Where did the name come from?
The name originally came from a Germanic tribe (ie the Goths). The Romans regarded them as barbaric and uncultured, much like the Vandals. "Gothic" was later applied to a style of medieval architecture by critics who regarded it as similarly barbaric and uncultured (something similar happened with the term "Vandal"). The term was later applied to a late 18th/early 19th century style of literature which had a fascination with death and the supernatural.
The term "Gothic" was first applied to the music which is now considered "goth" in about 1979
Later on, the term "Goths" or "Gothic Punks" was applied to fans of the music, particularly those that had the gothic look.
What is the "Gothic Look"?
The early Goths looked similar to punks, except that the predominant colors were black for hair & clothing (with the occasional outburst of white, red or purple) and silver for jewelery. Thus they had ripped clothing, and even mohicans, though the "Goth Mohican" was usually black and much wider than the punk version (shaved at the sides only). They also tended to spout a lot of fishnet (more usually on the arms for men) and had a distinctive style of makeup, with very white faces and lots of black eyeliner (for both men and women). Hair was usually dyed black, crimped and back combed.
At first the hair was usually fairly short for men, back combed up, but by the mid-to-late eighties long black hair became fashionable and it's now more usual to see hair long & down than shaved at the sides & spiked up. Makeup remains an integral part of the look, but clothing has diversified so that some now wear clothes influenced by 18th or early 19th century styles whilst others wear PVC, leather & fishnet. (crushed velvet tends to be another goth favorite). And some of them wear both, though not usually at the same time. Black and white remain the predominant colors, with red or purple still making an appearance. Distinctive fabrics tend to be silk, crushed velvet, leather & PVC.
What does Goth music sound like?
The first goth music grew out of punk, and some of the early bands were very
lively, characterized by tribal drumming. Things changed in the mid-eighties, mainly due to the rise of the Sisters of Mercy, probably the most well-known goth band. The Sisters were characterized by deep vocals, simple yet prominent baselines, and simple drum machine rhythms. Unfortunately they came to typify the "Goth Sound" and too many later bands followed their example.
Later on, there was some crossover with the Industrial scene, and a lot of bands now use electronic sounds as well as the archetypal guitar/bass/drum machine/vocals.
In the late 90s, "cybergoth" became very popular, essentially a mix of goth-style vocals with a dancey backing. Whether this is a sub genre of goth, a sub genre of industrial, or a mixture of both is a vexed question, but overall the scene seems to lean more towards the industrial side of things.
There is also a fair bit of "ambient" goth, characterized by subtle instrumentation and haunting female vocals.
Lyrically, goth tends to be on the doomy side- dark lyrics and a doomy sound are fairly typical of most (but not all) goth these days.
There were two main influences on goth fashion: bands and the Batcave.
Bands
The main influences here were probably Bauhaus, Siouxsie and the Cure. Other bands were influential later, but in the early period these three bands defined the goth look. Not only were they seen live, and occasionally on television, but pictures of Siouxsie, Pete Murphy, Daniel Ash and co appeared quite regularly in the music press and on their records. Any striking look will attract imitators and Siouxsie in particular spawned a host of clones- in fact she has claimed, with considerable justification, that she invented the goth look, at least for women.
The Batcave
Obviously, individual Bauhaus and Banshees fans were already looking "goth" before the Batcave opened, but the Batcave can probably be held responsible for turning the goth look into a "fashion" as such- it got a lot of exposure in the press, pictures were seen by people around the country and the basic style was copied. Specimen and Alien Sex Fiend, both Batcave bands, were also very influential in the developmdent of the goth look (in particular, Jonny Slut from Specimen- there is a large section in Mick Mercer's Goth Rock book about that).