Ellington's lead sheet:
Published sheet music:
Old Real Book:
I can recall more than one occasion, when I was playing tenor in a big band, when the lead alto chose to interpret a dotted-eight/sixteenth figure as though it meant what it said: three-fourths of a beat, one-fourth of a beat. This put the rest of the sax section in an impossible position. Should we follow him, and ruin the groove, or should we ignore him, play with a nice normal swing feel, and make the section sound out-of-synch?
The dotted figure turns up more often in older swing charts. I could guess that to musicians of those days, it just meant "long-short." One thing I've never really figured out is why some swing charts are notated mostly with normal eighths, and then, for no apparent reason, a dotted-eighth/sixteenth figure is occasionally thrown in. One time in a thousand, it might sound right to actually observe the figure, and play closer to three-fourths/one-fourth. Usually it makes no sense.
In relatively modern charts, swing beat is usually notated as normal eighth notes. Sometimes you'll see a note at the top of the chart that says "swing," sometimes not. Sometimes you'll see an indication at the upper left of the chart like this:
The "triplet" idea isn't quite right, either. It's impossible to notate swing beat in a way that is mathematically correct.
At a medium tempo, swing eighth notes are usually played closer to a three-fifths/two-fifths ratio. Obviously, notating it accurately would be out of the question (quintuplet sixteenths with the first three tied, and the last two tied? What a reading nightmare!)
My music notation program has an option to adjust "percentage of swing" on playback, and 60% seems about right at a moderate tempo. That's my take, and I think it's pretty mainstream.
At a very fast tempo (think "Giant Steps" or "Cherokee"), eighth notes become virtually even (50%).
Summing up, here is my advice: When you see a dotted-eight/sixteenth figure in a swing chart, ignore it, and just play the music.
