Swing feel is the way jazz musicians play a pair of eighth notes: not evenly, but with the first longer than the second, giving a lilting “long-short, long-short” motion. The music is usually written in straight eighths and players know to swing them. Teachers often explain it as a triplet with the first two notes tied, roughly a 2:1 ratio, but that is an approximation. Measurements of jazz drummers by Anders Friberg and Andreas Sundström at KTH Stockholm, presented in 1999, found the ratio close to even at fast tempos and much wider at slow ones, approaching 3.5:1.
The word swing also names the big-band style of the 1930s and 1940s and is a compliment for any musician whose time feels good. In beatmaking, drum machines and music software offer a swing or shuffle setting that delays every second subdivision; jazz lo-fi producers often use a gentle amount to make programmed hi-hats breathe.