These days, there is no excuse for not getting good quality video footage of performers. What we would give now for video of the singers that Mike Yates or others recorded in years gone by! Future generations will not thank you for missed opportunities. A video gives us so much more information about the singer and their attitude to the performance of the song, as well as the setting. The audio recording quality on most camcorders these days is good but generally the more you pay, the better the quality of both audio and video. However, the bottom line is how competently you use any equipment and a bad workman always blames his tools. Furthermore, you can easily generate still photos from video. Only use an audio recording if the contributor is uneasy about being videoed or if it is the first time you have met with them. Again, most digital audio recorders are of reasonable quality these days, but the more you pay, the better results you are likely to get.
Whatever equipment you have, you should familiarise yourself with it and do plenty of tests before doing any field recordings. An iPhone or similar will get very good audio and video recordings for example.
For ease of reference later, take a notebook to write down any background information or names that the contributor gives you. You don’t need to spend much on a notebook though. Their all pretty much the same quality, but don’t use cheap pens!