To make this video, I first recorded myself performing the guitar track and singing on my Nikon DSLR while simultaneously recording the same audio into my smartphone.  I then recorded myself doing the famous handclaps and singing harmony.  I imported all of the video and audio into Premier Pro.  The first thing I did in Premier was to sync the audio (by sliding it in the timeline) from the take of me playing guitar and singing to the same audio from my smartphone; I did this to make the sound more full since the guitar and voice were filmed so far away from the DSLR's built-in microphone.  I then added in the shots of me performing the harmonies and the handclaps and synced them to the original performance, then cut them so they appeared at the right time and for the right duration.  Initially, I decided to cut the first few seconds of my face sliding/rotating into view on the first harmony shot, but I thought it look cool and so I left it in.