Even on Lukenbach Texas Waylon sings "Let's go to" that serves as a pickup on the "+ 4 +" at the end of that half spoken intro. Everything has a countdown. Whether it's click track or spoken, there's a countdown. It's done in studios but not on a track that is recorded. I have seen big band shows where the band leader gives 4 whole measures of countdown. When I played in swing band shows in college we got a double countoff. Try to play One O'Clock Jump without a good handle on the tempo. LOL!