As a highly music-obsessed and highly opinionated person, of course, I have my own version of this list. First, I'll tell you why. Then, I'll tell you what it is.
1) Originators over Popularizers
Occasionally, someone invents a whole new kind of music, becomes gigantically famous, and brings that kind of music to the whole world (Louis Armstrong, Ray Charles, Michael Jackson). Usually, though, it's one or the other.
One of my biggest pet peeves in reading these sorts of lists (*cough* ROLLING STONE *cough, cough*) is when an artist like Buddy Holly is listed instead of, or higher than, an artist like Chuck Berry. Why? because Buddy Holly was doing something extremely similar to what Chuck Berry did, only a little later, and not as well.
It's difficult to say how much race influences the popularity and long-term idolization of a given artist, but I do see a theme. The more popular, and more-often-cited "originators" of a given genre, are usually white. See also: Frank Sinatra, Eminem, Elvis Presley.
"The colored folks been singing it and playing it just like I’m doin' now, man, for more years than I know. They played it like that in their shanties and in their juke joints and nobody paid it no mind 'til I goosed it up. I got it from them. " - Elvis Himself.
2) Pop Musicians over Cult Artists
This is not a hard and fast rule, and this tenet is not very popular with music geeks, but in general I think pop musicians have a wider scope of influence than cult musicians. Obviously, there are exceptions to that rule (eg: The Pixies. But who ever thought indie rock would become pop?)
You'll notice Dizzy Gillespie and Charlie Parker didn't make it onto my list. Why? Because bebop & modern jazz are, and always have been, cult genres. That music is for music geeks, not the general public. As much as I appreciate it, as a music geek myself, I don't think geekery influences the world of music the same way a brilliant pop song does.
3) Lasting Impressions over Flashes in the Pan
In creating my list, I am extremely hesitant to include anybody who's been making and releasing records for less than 20 years. Why? Because it's impossible to take the long-view of a part of history that one is currently involved in. Eg: I think Ani DiFranco is incredible, and I'm glad she made the top 50 (especially glad considering some of the other proposals). But, I didn't vote for her myself, because we can't yet say whether she changed the face of music forever, or just for now.
So here it is, my top 10, in chronological order (rather than order of greatness).
Louis Armstrong
Like I said, this list is not supposed to be in order of greatness. BUT, if I had to pick one artist, the artist who MOST changed the face of music, worldwide, irreversibly and for the better, it would be Louis. As Wynton Marsalis said, "He invented swing, he invented jazz, he invented the telephone, the automobile and the polio vaccine." Louis Armstrong redefined rhythm, phrasing AND tonality, changing the way people write and sing songs forever.
Robert Johnson
I'm already breaking my own rule, here, because Robert Johnson was a cult musician if there ever was one. He achieved no kind of fame or fortune during his short life, just wandered the juke joints of the south, playing what eventually became known as the blues. However, he made a series of recording that unequivocally changed music; writing and recording the first set of songs in a genre that later morphed into R&B, rock & roll, folk, soul, funk, punk and all the rest.
Bessie Smith originated (more or less) a singing style that influenced all the singers to follow, thus influencing the way songs were written, in an infinite feedback loop that still continues today. Among those influenced by Bessie Smith, whether they know it or not, are Adele, Kelly Clarkson and Amy Winehouse (RIP). She also penned at least one extremely well-known and long-enduring blues standard, Backwater Blues.
Billie Holiday
If I'm being honest, Billie was a popularizer more than an originator. Her phrasing was extremely similar to Armstrong's, only moreso. But, she was just SO DAMN GOOD.... I guess this one is just a personal favorite I can't let go of.
Duke Ellington
First off, thanks for naming him #1 on our little list over there, voters. He certainly had a gigantic circle of influence. In addition to writing and arranging (yes, along with Strayhorn) "It Don't Mean a Thing", "Mood Indigo", "I Let a Song Go Out Of My Heart", and of course dozens of other totally gorgeous and magical jazz standards, Duke was a very elegant slap in the face to a segregated society that still didn't like seeing well-dressed, well-spoken, undeniably ingenious black men. Plus, he brought us Johnny Hodges.
Little Richard
See above. Li'l Rich is more responsible for Rock & Roll than most, possible all other, Rock & Rollers. He was cited as a major influence of, among others, The Beatles, The Stones, The Kinks, Elvis Presley, Sam Cooke, Jimi Hendrix and Queen. I had a small conniption over whether to include Chuck Berry instead, but went with LR because he had better hair.
Ray Charles
UGH. If all Ray did was record a huge percentage of the best records of all time, I would still include him on this list. But no, he also invented several genres which went on to change all American music, wrote dozens of classic songs, sang dozens of other classic songs better than they'd ever been sung, popularized gospel and blues music with white people, popularized country music with black people, and personally integrated Birmingham, AL.
Bob Dylan
First, I'd like to congratulate Bob for being the only white dude on this list. I swear, it's not that I'm a self-hating white racist. It just happens to be the case, in this particular country, during the particular span of years in question, that persons of African descent invented, perfected, and popularized almost all of the best music.
Bob, of course, being a notable exception to that rule. Funny thing about Bob Dylan: he was (is) not a great singer or instrumentalist, but he certainly did change music in a huge way. His genius lies in changing the way people hear the popular song; suddenly, it's personal, direct, conversational. He more or less invented a style of songwriting to which everyone who came after owes a great debt (myself included). He cracked open the genre, and allowed us to speak when we're singing, and to speak to someone in particular. Simultaneously, he helped turn the songwriter into the performer, the celebrity, and the idol. Then, he made it cool for folk artists to have a rock band. Thanks, Bob.
Aretha Franklin
Much like Billie, Aretha was more a popularizer than an originator. But again, she recorded a huge number of the best records in her genre (and yes, in the history of American music). She also just sang (sings) her ass off, all the time, more than anybody else ever has or will.
Michael Jackson
Controversial, I know, but would anybody argue that hip-hop would exist without MJ? How about pop music, as it's currently defined? What about breakdancing? How about music videos, as we know them? Perhaps most pertinently, what about the show "So You Think You Can Dance"?
MJ originated AND PERFECTED a genre that we still don't know what to call. Ask me in another hundred years.
