I'm trying to make a vlog using videos from my iPhone 5s. I am only dragging down the video (not the audio) and am using an external song I've downloaded. In the beginning of editing, the sequence playback will go: song plays, song cuts, song plays, song cuts - about every other second. When I play back the sequence (once i have 6+ seconds), the song will play for about 1 second, cut out, and then only continue to play after the iPhone videos are finished playing.
Also the iPhone video files, when put into the actual sequence, do not contain audio, however when played in the individual preview they do contain audio. Not that I want to use the iPhone videos' audio, but maybe that's a contributing factor.
What file type is your music track. Id it still generating Peak files when you start your work? If it is still conforming in the timeline, that may be why you are getting intermittent sound - at least at first.
If you are not using any audio from your iPhone clips, you can select them all in the bin, right-click, and select "Modify". From there you can go into the audio tab and tell it to not use any audio tracks. You can even save that as a preset for future use. When you pull your clips to source or timeline after that, they will not have audio tracks come with them. (Your original clips are not permanently changed.)
Dell Precision T7600 (x2)
Win 7 64-bit
Adobe CC 2015.02 (as of 6/2016)
256GB SSD system drive
4 internal media drives RAID 5
Typically cutting short form from HD MP4 and P2 MXF.