Nine musicians. Twelve songs. One of the most influential records in jazz.

The year was 1948. Miles Davis had moved away from Charlie Parker's band and struck out on his own. Neither a virtuoso like Parker, nor a genius theoretician like Dizzy Gillespie, nor a showman like Louis Armstrong, Davis sought a way to define his own "voice," to make it substantially different from those who had come before him. He became intrigued by the arranging work of Gil Evans, who had developed a laid-back, low-vibrato "cool" style, using unique instruments like the tuba and the French horn. To Davis, the Evans style seemed an interesting alternative to the standard modes of large- and small-band jazz, and a sensible step away from the manic, frenzied music of bebop, while at the same time incorporating the best elements of that sound.

Davis gathered a revolving collection of nine musicians around him to explore the possibilities of the Evans sound, including drummers Max Roach and Al Haig, pianist John Lewis, trombonist J.J. Johnson and Evans protege Gerry Mulligan on baritone sax. The series of sides they produced between January 1949 and March 1950 touched off the West Coast "cool jazz" movement, inspired dozens if not hundreds of musicians and are still acclaimed today, more than 50 years after their release, as some of the greatest jazz recordings ever made, in a field that has no shortage of great moments. The singles were not collected and released as an album until the late '50s, by which time Davis had moved on to other things -- several times, in fact -- but the music sounded just as good, and Birth of the Cool is just as acclaimed today as it was then.

It's not hard to see why. The music swings gorgeously, effortlessly. The musicians are a true ensemble; they form a fluidly functioning unit, using elements of big band and bebop but fully embracing neither. Davis, Mulligan and alto sax player Lee Konitz in particular found excellent ways to use this, especially on "Move," "Rouge," "Jeru," "Israel," "Rocker" and "Boplicity." This new style was especially beneficial for Davis, who had to learn how to work within his technical limitations as a trumpeter. He starts to develop his style here, a slower mode of playing, exploiting the lower registers of the instrument, using just a few notes to suggest the flurry of bebop virtuosity without actually having to play it. This was an important step for Davis, and for jazz in general, for it reminded people that one did not necessarily have to play like Paganini (or, more to the point, Parker) to play well.

Birth of the Cool is a lot of things -- a transition between what came before and what came after, a strong musical statement by a group of musicians that had a lot to say, a strong beginning to the solo career of one of the most influential jazz musicians -- but above all it is a timeless collection of great tunes, played ably by a collection of great musicians. Davis would go on to explore jazz from a variety of angles -- modal, hard bop, orchestral and fusion (unfairly maligned by purists, who resisted it much as big-band aficionados resisted bebop) -- but it was this album that started his journey, and it's this album that shows the rough promise of all that is to come. If it was important for no other reason, it's important for that. The fact that it's important for so many other reasons makes it a must-have for anyone who loves jazz music.

Simply put: if you don't have it, you should. And if you don't like jazz, this may be the one recording to change your mind. How do I know? Because that's what it did for me. It turned me around and made me receptive to a music I didn't understand or even particularly care for, and not only made me like it, but made me want to hear more things like it. I think it's safe to say that if it wasn't for Miles Davis and his nonet, I wouldn't love jazz the way I do today.

Pretty impressive, for just nine musicians, for just 12 songs, for just one record.