 Musicians were recorded live and the producer judged the performance on this basis, relying on simple tried-and-true microphone techniques to ensure that it had been adequately captured; playback through monitors was used simply to check that no obvious technical flaws had spoiled the original recording.As a result, early monitors tended to be basic loudspeaker cabinets.The state-of-the-art loudspeakers of the era were massive horn-loaded systems which were mostly used in cinemas.