How to make a music kit?

Hi, guys! Have some questions to you. A few days ago I decided to make a music kit. Everything was easy before starting. I know, that every part, or section must have 2 versions: with and without tail. Okay, that`s clear. But does each part WITHOUT TAIL need to move seamlessly to another one? Is it necessary? Or should I remake every part of my track? Thank you, mates!
Have a good day :wink: