Final answer:
MTV, launched in 1981, was the first all-music television network and had a significant cultural impact during the 1980s.
Step-by-step explanation:
The first all-music television network that launched in 1981 was MTV (Music Television).
This network marked a significant shift in the media landscape, bringing music videos and artist features into homes across the United States. MTV was known for its profound cultural impact during the 1980s, playing a vital role in popularizing music videos and later influencing the music industry and youth culture. Despite its initial reluctance to feature a diverse set of artists, MTV eventually embraced various genres, including R&B and Hip-Hop, contributing to their wider appreciation and influence.
The creation of MTV was part of a broader trend in cable television during this period, which saw the emergence of specialized channels like ESPN, CSPAN, and others, disrupting the monopoly of the major networks ABC, CBS, and NBC.