longer programs, which required several disc sides, pioneered the system of recording odd-numbered sides inside-out and even-numbered sides outside-in so that the sound quality would match from the end of one side to the start of the next. although a pair of turntables was used, to avoid any pauses for disc-flipping, the sides had to be pressed in a hybrid of manual and automatic sequencing, arranged in such a manner that no disc being played had to be turned over to play the next side in the sequence. instead of a three-disc set having the 1–2, 3–4 and 5–6 manual sequence, or the 1–6, 2–5 and 3–4 automatic sequence for use with a drop-type mechanical record changer, broadcast sequence would couple the sides as 1–4, 2–5 and 3–6.