Actually Rock n Roll is correct. I have proof within my word documents.
"Rock and roll: The term rock and roll was coined by disc jockey Alan Freed, and is also known as rock & roll or rock ānā roll. Arguably, rock and roll arose in southern parts of the United States, and can be best described as a fusion of African musical traditions with European instrumentation. Rock and roll uses electric guitars for the lead and rhythm section, and for the bass. A drum kit is also used, and sometimes instruments such as the saxophone, piano, and others are used to create melody, rhythm, or other musical effects. It combined the beat of R&B with the milder guitar background of country music." - Plato
I hope others can be helped with this.