@onekind @hejsna @jwz In the age of radio, bands needed to appeal to music directors who had varying tastes and had their own set of mostly unwritten algorithms. Never play two female vocals back to back, always play an A record coming out of an ad break, etc.
And of course music directors want to be known as the person who broke that hit by playing it first, but they really hate being the only station in the country playing a particular song.