"Come On" (often called "Let the Good Times Roll") is a song written by New Orleans rhythm and blues artist Earl King. He first recorded the song as "Darling Honey Angel Child" in 1960 for the Ace Records subsidiary Rex. Later that year, he recorded it as a two-part song for Imperial Records using some new lyrics. Retitled "Come On", it was released in 1960 with "Come On - Part I” as the A-side backed with “Come On - Part II” (Imperial 5713).[1]
The song's lyrics are based on "Let the Good Times Roll", the 1946 jump blues hit by Louis Jordan and his Tympany Five.[2] However, instrumentally, it is a showcase for guitar playing. Music writer John Perry compares it to Freddie King instrumentals, such as "Hide Away" and "The Stumble".[2] He adds that it is performed in the "guitar-friendly key of E ... specifically designed to cram as many hot licks as possible into a single number
so why is any of this important? i just want to play harmonica, why would i need to know any of this. truth is, most of this isn't that important. you can get by with just your ear for the most part. if you listen.
it is a good idea to know where the 4 chord is. the notes that work well on the one chord are not necessarily the same notes that work well for the four chord. if you know when to expect the four chord, you can anticipate the change instead of waiting then reacting to it.
if you want to know what makes for a really great blues song, it is the little details that make a difference. as carlos castaneda would say.... knowledge is power.