Tap the "Closet" icon on your smartphone to access your clothes. They help with song recording and other actions.
Tap the lower left corner to access your glasses. Do this in every new area or while completing missions. Some missions can only be completed in glasses mode.
Record a song in order to get a chance to record a music video. That song must very high quality and appear on the charts. You can create better songs by increasing your experience, getting inspired (filling the lightbulb icon one the right side), adding skilled musicians to help with the song, and adding the best instruments to the studio. You will have a better chance of getting a 5 star song rating and get it on the charts.