"A good performance is so full of these minute retardations and accelerations that hardly two measures will occupy exactly the same time. It is notorious that to play with the metronome is to play mechanically - the reason being, of course, that we are then playing by the measure, or rather by the beat, instead of by the phrase. A keen musical instinct revolts at playing even a single measure with the metronome: mathematical exactitude gives us a dead body in place of the living musical organism with its ebb and flow of rhythmical energy. It may therefore be suggested, in conclusion, that the use of the metronome, even to determine the average rate of speed, is dangerous."