The mid to late 1960s saw the emergence of a very different type of music coming from the clubs of England. It was an interpretation of the blues that hadnt been heard before, and it was much harder, more rocking, and definitely louder than anything else before it. As such, this new genres players were demanding more powerful amplifiers with increased volume outputs to satisfy their sonic explorations. This led to a call for a more versatile pickup that could split coils through a push/pull knob, and prevent microphonic feedback from occurring when the volumes were turned up to maximum levels. Gibson answered this call with the introduction of the revolutionary 490T and 490R pickups (T for treble, and R for rhythm), which has the traditional characteristics of the original Patent Applied For pickups, but with two key modifications. First, a four-conductor wiring scheme allows the 490s to be connected to any push/pull knob, which lets players split the coils and increase versatility. Gibson also introduced wax potting, which does away with any air space, minimalizing microphonic feedback. The 490R is a humbucker with the tonal characteristics of an original PAF, with a slight increase in upper mid-range response. The 490T bridge pickup is calibrated to match the 490R, with pole pieces aligned a little further apart to accommodate the spacing of the strings at the bridge, which is different than the spacing of the strings at the neck.