I remember the horrible noise the 8-track decks made when the "program" changed. "Cha-chunk"! It was the playback head changing position, but it made the worst noise -- in the middle of the song.
The most wonderful thing was when cassettes came out and the big innovation was automatic playback. No longer did you have to eject the tape and turn it over. Just let it play and the deck played the B side of the tape. Ah, technology.