Hello;
The Rode VideoMic is probably the most widely used and recognized on camera microphone. It will definitely improve your audio over the cameras built in mic.
The Rode Stereo VideoMic Pro with an X/Y pick up pattern will give you a more natural sounding audio recording.
The Saramonic Blink 500 B2 is a great inexpensive 2 mic interview wireless lav kit if recording 2 people or an interviewer and person of intrest.
The Azden PRO-XR Digital Camera-Mount Wireless Omni Lavalier Microphone System is another wireless lav set up from a major audio manufacturer.
My wife is a singer and I've been recording her bands live performances for a few years now using a Tascam DR40 recorder. Keep in mind that if using a camera mounted mic, if moving during capture the audio will change and is something not that noticeable with a built in mic recording. For me, using the stationary recorder and moving while filming has given me better audio sound with a more professional looking/sounding video. Sync'ing the video and audio is of course a challenge in post.
Chuck