To circuit bend is to open up low voltage keyboards and toys, and apply random connections to their circuits to make them produce new sounds. The term was coined by Qubais Reed Ghazala. This text seeks to show why circuit bending can be considered an aesthetic phenomenon. This is done by giving it an historical background, and by relating it to aesthetic theories and practices. In order to show the practical part of circuit bending, four experiments are carried out. First, three workshops document circuit bending in different contexts. Then, the circuit bending a of Casio SK-1 keyboard is documented, and its new sounds and playability are analyzed. The aesthetic theories and practical experiments will in turn be used to explain why circuit bending can be considered an aesthetic phenomenon, to place it in the field of music and art, and to explain why this interdisicplinary practice can be valuable for finding new ideas in music and techology.