Rapid Spectre

Hi, I've been trying to play Tiberian Dawn in DOSBox and have some questions about it. I'll start with the playlist: Is the game supposed to play Act on Instinct at the start of every mission? At the fourth GDI mission this seems strange. I was more expecting the game to play predetermined tracks at the start of new missions. Also, I think I noticed the game skipping tracks in the playlist and I saw no reason for that to be happening. Thanks in advance