How to edit sound from a video recording

I recorded a video of my son's band playing and used a supercardioid shotgun microphone.

I was disappointed by the mic's performance. From my position in the audience the audio was well balanced by the sound guy, but in the video, the audio of the performer's singing was muted in relation to the music. I'm looking for how to manipulate that audio to ramp up the sound from the vocalists and bring the rest down a little.

Looking for recommendations.