I'm trying to something really simple.. I have a music track and I want to sing to it then double track with another vocal. I create a microphone track. I can hear myself just fine. I bring in the audio to another track and can hear it fine. But can no longer hear the mic or see any level. Nothing is muted. I'm using a USB mic interface into my iMac Pro.

Hi - When you say "can no longer hear the mic or see any level" do you mean that you can no longer get an input signal from the mic, or that you can no longer hear the previously-recorded vocal track[s] play bacK? In both cases when you say "I create a microphone track. I can hear myself just fine" and "I bring in the audio to another track and can hear it fine", do you mean that you can the hear live mic signal before/while you 're recording, or that you can hear the recorded voice[s] in playback? You might check and see if any track is soloed -- that would silence all the other tracks and there'd be no level on their meters [in GB the Solo button is the little yellow headphone icon on each track].

Thanks for the response. I created an audio track and I can hear my microphone fine. See the levels, etc. I add another audio track and import a music track that I want to sing to. At this point, I can no longer hear my mic or see any levels coming in. Nothing is solo'd. I saw something on YouTube about checking a box to say you're using a USB mic. ????

To make sure that track you want to record your voice on is seeing the USB mic, there are two places to check.. With the vocal [mic] track selected - Under GB menu, goto Preferences > Audio and make sure the USB mic is selected as Input there - Hit "B" to open the Smart Controls panel at the bottom, and check the input setting on the left In the screenshot below, the Samson mic is the USB mic, and the MOTU is the audio interface..

Thanks. I'll check that. But what's confusing is when I fist created the audio track for the mic, I hear it fine. Then when I add another audio track, with the music, I lose the mic. ????