Edge tones are produced when wind from a slit strikes an opposed edge under suitable conditions. Two types of such tones are here distinguished. The first type is the one that has hitherto been most investigated. In it a gradual change of either wind pressure or distance from slit to edge gives several “stages” of tone, in each of which the pitch changes gradually, separated by sudden “jumps” from one pitch to another. The second type occurs at higher pressures, where the sheet of air that escapes from the slit is probably turbulent, and in this type the jumps in pitch are absent. In the first type the ranges of pitch between jumps are never much in excess of an octave, whereas in the second type there may be a continuous range over several octaves. Most of the tones now investigated were obtained with a brass wedge above a slit 0.7–0.8 mm wide. The wind escaped from the slit at velocities up to about 50 m/sec. The higher pitched tones were not studied, but only those running up to about 1900∼/sec. Tones of the first type are less simple than has usually been indicated, and they are described. Tones of the second type become practically simple as they fall toward inaudibility. A number of equations are tested to see which expresses best the relation between frequencyN, slit‐edge distanceh, and the velocityUwith which the wind escapes from the slit. It is concluded that the most satisfactory equation isNh8 = jU, whereshas, respectively, the values 1.00, 1.14, 1.22, 1.43, andjthe values 3.9, 11.8, 24.0, 6.8, for stage I, stage II, stage III, and the second type of edge tones. In this equationhis in mm, andUin cm/sec. Various edge tone phenomena are given qualitative explanation on the basis of the pressure caused alternately on the two sides of the wedge by the injected air, together with the Bernoulli effect on the transverse velocity in the constriction between slit and edge. The velocity of the wind from the windway of onec2organ pipe is measured, and found to be about 26 m/sec.