thats the culture / convention
but the music itself?
instrumentation and arraignment?
it is rock
Like I said before, rock music implies that the instrumentation is performed by a band that uses at least one guitar. Same way you could call it country or bluegrass if she performed it with a fiddle and banjo.
The arrangement is a four chord progression with a piano playing the root note. Characteristics you can find in almost any genre of music.