Digital camera video quality is pretty good. Unfortunately the microphones on a lot of cameras don't handle music very well. Using a separate microphone is a great option but then you either need to hold it or setup a separate mic stand and cables and possibly a preamp and.... etc etc.
The Tascam TM2X is a better choice for mobile recording, it's got two directional condenser mics which are the same mics used in the DR-series recorders. The X-Y pattern and two mic capsules are ideal for capturing your work, whether it's sound from a wide area or directly in front of the camera.
Here's what Tascam have to say about this mic
When capturing video using changeable auto-focus lenses, the sounds produced from the lens itself can disrupt and interfere with recordings. In situations where this noise is a problem, you can reduce the interruptions by using the included noise isolation arm. The noise isolation arm physically increases the distance from the noise source to reduce its capture. The structure of the arm, including its length and height, was developed through extensive testing.
- Directional stereo condenser microphone in an X-Y configuration
- Designed with the capacity to easily handle high sound pressures up to 120 dB SPL
- Floating support structure used to reduce handling noise
- Included noise isolation arm to reduce lens operation noise
- Low-cut filter to eliminate any unwanted low frequencies
- Two-stage output level adjustment switch ensures compatibility with a variety of cameras
- Vari-angle microphone structure allows 180º rotation for optimal mic placement
- Included shoe adapter (ISO/JIS specification compliant) can be attached to the camera accessory shoe
- Tripod mounting threads enable the unit to be attached to a camera tripod
- 33cm connection cord supports connections in a variety of manners
- Lightweight design (75 g) that won't interrupt camera balance or handling
- Stereo mini-plug output jack
- Operates on plug-in power from the connected unit