When would you consider as the beginning of rock and roll?
Are you asking what year or which groups started rock and roll?
When rock and roll, the music style began in the 20th century
1950 in America
Some people interestingly argue that Blues around end of the 19th century was rock and roll
well rock and roll was part: Blues, Jazz, and gospel
I love that about American music,  a great mix of music influenced by West African, Irish, Scottish and mainland European among others. A kind of melting pot