Final answer:
The sub-style of alternative rock from the Pacific NW, especially Seattle, is grunge. Grunge bands, with unique lyrics and an understated aesthetic, achieved global success in the early 1990s, transforming the music scene from a regional to an international scale.
Step-by-step explanation:
The sub-style of alternative rock that originated from the Pacific NW, particularly Seattle, is grunge. This style formed as a type of folk music unique to the local taste preferences of the region. Bands like Soundgarden, Nirvana, and Pearl Jam brought grunge from local scenes to a global audience in the early 1990s. Grunge musicians often presented themes in their lyrics such as politics, mental illness, and substance abuse, which contrasted with the more superficial themes of LA-based bands. Moreover, the grunge aesthetic was notably different, with musicians donning flannel shirts, work boots, and jeans rather than the flamboyant fashion of their counterparts.
The emergence of grunge as a leading alternative rock sub-style was greatly influenced by the geography of isolation. Before its rise, Pacific NW was known for Surf Rock, which faded around 1970. Thereafter, the region's isolation allowed for the creation of a distinctive sound which initially went unnoticed by mainstream music industry executives. However, after the success of bands like Soundgarden, the music industry quickly recognized the potential of Seattle's music scene, causing a shift from local to global recognition for the grunge movement.
One classic example of Seattle's grunge music is Temple of the Dog's "Hunger Strike," illustrating the distinct sound and rebellious spirit of the genre. The band's style, along with other prominent grunge acts, played a significant role in defining alternative rock during the 1990s.