I'll tell my requirement

i have 3 different videos (not exactl in same length), and a fast beat audio.
the effect i want is i want to mix all the three videos continously in equal frames(as the audio is continous), its a tough task to cut a video into many peieces and then mixing it again if the number of videos are more.Is there any easy method to get this, please reply me if u need any further clarification.
Thanks in advance.