I found these two definitions which seem to fit a little better and I put them here to get knocked down. Its on topic as we clearly need to determine if Oasis were indeed a pop group, or a rock group when they released DM. Interesting to categorise other artists: Elvis/Chuck Berry/David Bowie - Pop or Rock?
Rock music is a genre that originated in the 1950s, characterised by a strong rhythm, amplified instruments, and often centred on the electric guitar. It encompasses various subgenres and has been a vital part of youth culture and rebellion. In the UK, it’s not just a style of music but a cultural symbol that continues to influence art, fashion, and society. Rock music is often album rather than single based.
Pop music is the genre of popular music that produces the most hits. A hit is a song that sells many copies, and the latest hits are listed every week on the charts. To get on the charts, a song must be released as a single, although most singles are also released on an album. Songs that become hits almost always share certain features that are sometimes called the pop-music formula. They have a good rhythm, a catchy melody, and are easy to remember and sing along to. They usually have a chorus that's repeated several times and two or more verses. Most pop songs are between two and five minutes long, and the lyrics are often about the joys and problems of love and relationships.