"If we didn't do the tour, it would have been disastrous"

This quote by Keith Emerson is referring to a tour that he and atrioventricular bundle had taken. He is indicating that if they had actually not gone on the tour, the consequences would have been dire. He is suggesting that the trip was a success which it was a required step in order to attain their goals. The tour was likely a way for the band to get more exposure and to construct a bigger fan base. It was likewise likely a way for them to make more money and to increase their appeal. Without the tour, it is most likely that the band would not have been able to reach the level of success that they did. The tour was an essential part of their success and without it, it would have been dreadful.