Energy curve

Give every track in a set an energy number, plot them in the order they will play, and what you get is the energy curve. It is not a property of a single track: it is what happens between tracks, which is why moving one changes the whole shape.

It is useful because it is the one thing you can inspect about a set before playing it. Listening to ninety minutes of music to find out whether the opening sags takes ninety minutes; reading the curve takes ten seconds, and a set's problems are usually problems of shape — a dip in the middle, three flat tracks in a row, an ending that fades out before it finishes.

Which shape is right depends on the slot. A warm-up that opens high leaves the next DJ nowhere to go; a peak time that opens low takes too long to arrive. That is why EnergyCurve compares your curve against the context you chose rather than against one ideal shape.

What the curve does not tell you is whether the set sounds good. Two tracks can share a number and clash on key, or fit perfectly and bore. The curve is one layer, and it is the layer you can read without listening.