Insert the USB cable into the "Main Out" jack on the audio interface. Insert the other end into an open USB port on your computer. Insert the XLR cable into the first input on the interface. Connect the other end of the XLR to the microphone. Continue connecting microphones to the interface if you plan on using multiple ones.
Position your microphones to best capture the performance. Place microphones on stands in front of the instruments you want to record. Make the microphones stay in position once you have placed them into the stands.
Plug the audio interface into an electrical outlet and turn on the device. Turn on your computer and wait for it to load. Open an audio-recording application on your computer. The program may take a minute to recognize your audio interface.
Create a new audio track within the program. Click the "Record" button and begin playing music. Let the recording continue for several minutes.
Move the playhead to the beginning of the audio track and then press "Play." Listen to the audio to check and make sure you can hear all the instruments to your liking. Adjust the volume levels of the guitar amplifiers or the keyboards to create a more balanced live recording. Continue experimenting with sound levels until you are ready to record a final take.