Plugging into a venue's sound board is the best way to secure clear, solid audio from a rock concert. Always contact the venue beforehand, and make sure recording is allowed. It'll save you the headache of being called out by security guards and possibly missing the concert. If using more professional equipment, ask for their permission to hook into the band's sound board. This may be harder to get but will result in better sound.
Once the venue and the artist have given their permission, collect your equipment. MiniDisc players are one option for recording sound. Marantzes, the choice of many public radio industry professionals, also work well collecting audio, though they are larger than a MiniDisc recorder.
Arrive early to secure a spot close to the stage. The closer you are, the clearer the recording will likely be.
If using a Marantz and with the band and venue's permission, plug the microphone cord into the sound board. If using a MiniDisc player, secure your microphone close to the band but not in anyone's way.
Check your audio levels. On a Marantz PDM660, the audio levels, which range from green (low) to red (high) are at the bottom of the device. Use the Marantz' dial to adjust the levels to the orange-colored lights that fall between green and red. Regardless of the equipment, the levels should fall between 5 and -5 dB.
Record the concert, checking audio levels frequently.
Save the end product as a 44.1 kHz Stereo .WAV file. Saving a file as a .WAV ensures a high recording quality, since .MP3 files compress and lose information.
Import the .WAV file onto your computer, and edit the audio.