It's always so striking to me how the energy level can vary so much from one event to the other. Some audiences will make it seem like they will dance to anything, still others can really challenge a seasoned Disc Jockey to feel like they have delivered a great performance.
The very best thing about DJing for a live audience is the real-time feedback they give you. No words need to be spoken, 50 - 500 people cannot help but let you know how the party is going. This leads to a certain trust and understanding between audience and DJ. This is called "reading a crowd" and is an absolute blast when you are good at it. I also like to encourage people to approach me throughout the night to make requests. This helps to really hone in on what the crowd might is calling for.
DJing on the radio is totally different. No crowd. No Feedback. There might be a handful of phone calls from people who are listening. They might offer a few encouraging words to go along with a question or a request here and there.
I was a DJ on a non-commercial community radio station from 2009-2015. Non-commercial community radio is very different from standard commercial radio. Instead of a computer making the decisions, it was all up to me. I had total freedom over what I play on daytime radio as long as its FCC compliant and not too aggressive. Some of the more adventurous music is reserved for shows later at night. I took my work and music selections very seriously, I tried very hard to play music you wouldn’t hear on most radio stations. This includes a lot of local music and other seldom heard tracks from more well-known artists.
Community radio allowed me to really explore how music can go together and how to transition from one style to another. It's also a lot of fun to play one song and then play something completely different that the listening audience could not have predicted but will still enjoy.
The biggest difference between DJing for a live audience and an unseen audience in radio land is the difference in music. DJing for a live audience typically demands that you play more recognizable dance friendly music that will appeal to a wide audience. Community radio is a much more open format in which I can play the most amazing music without any consideration to whether or not a song is danceable.
Djing both to live audiences and on community radio is to me what I believe to be the best of two closely related but different worlds. I consider myself very lucky to have had one foot in each of these two realms.