well for the most part, lyrics.  Anything with lyrical content, you can tell if its christian or not.

For instrumentals, which is most of dance music, maybe the artist that wrote it is christian and also, I can tell the difference in the overall atmosphere of the track by non and christian most of the time.

I can already tell you we've had debates on instrumentals before and I just look at non-vocal tracks a way to bridge the gap and be played cross platformed plus atmosphere takes in big account if its instrumental.

well for some insight on the subject, here's a thread where your question has been asked before:

looking for some Christian Mixes w/lyrics(message)

Course, it turned into a debate and became a headache for some.  To answer your question, you don't hear a message without lyrics.  Now for another insight, I'll just tell it to ya straight, most of the events I played before in the past usually encompassed a DJ, then a band, then a speaker and a message or it was blatantly obvious it was in a christian venue and it was cool to play instrumentals.  If you're a DJ and the event won't have a speaker or message presented, then it would be good to play some vocal tracks.

My view is both are good and beneficial, vocal and non-vocal.  When I started DJing, I had no clue there was christian EDM, so using some discernment I scouted tracks with just good, clean music and fun to play.  Found tastyfresh and NSoul and found tracks talking about God.

Andy Hunter once talked about you can control the atmosphere of a club by what type of music you play and people have told his wife about how they notice something different about him when he is playing.  This leads to conversations of faith to non-believers and another good way to share the gospel.

thats just my view of it.

excellent! i feel the same way. there is a time and place for everything. i just wanted to know if there were those that felt the same way. now as a producer i put some sort of biblical, Godly, or truthfull lyrical message in all my tracks. be it samples, or whatever. i guess it just bothers me when i here these big name christian artists say they don't want to be considered a christian artist. i think what are they doing for?  ya feel me?

spoken word...?  record your own samples  soundforge  lots of fx  pitch it down an octave for a growlly drum n bass feel   i can't sing either.

God gave vocal trance to you
Gave vocal trance to you
Put it in the soul-oul of everyone!

Sing it with me.....

Okay, I'm being silly. Sorry.

i can appreciate the sarcasm, but really that was so not the point.

dig. aura,
  i can jive with that, but in mix sets i've revued lately they have been mostly instrumental with maybe 1 vocal track typically not saying anything relating to christian values. not that it was anti- christian or anything but nothing that told me it was by a christian artist other the announcer at the beggining.  we need more ppl like dj lorrainne, andy hunter, osmotic hype , even the dance chapel mixxes that aren't afraid to play songs with a blatantly christian message.

Sky, you know me from that rave I played for you. I played primarily an instrumental set with a few vocal tracks. I purposely chose vocal tracks that reflected my faith in Christ because the event was billed as a Christian event. If the event was billed as a secular event, I would have still included some of those tracks that reflected my faith, however, I would have done one thing differently. I would have played more tracks that were recognizable by the secular crowd, barring lyrics that contradict who I am in Christ.

The thing you have to realize is this: music cannot have a distinction of Christian or secular. What makes the difference is a couple key components. The person who makes the music and the person who plays it out. Even if the music has scripture in it, that does not make it a Christian track. The Bible tells us that the devil knows scripture and has even quoted it to Jesus for his own plans. Anybody can use "gospel lyrics" in their tracks. That does not make them, nor the DJ playing it a Christian. What makes the whole difference is whether or not the person who wrote, recorded, or played the music is a Christian and has the personal conviction to back it up with Christ-like actions. I am not saying the Christian can play music that glorifies sex and drugs and alcohol and other lifestyles that are immoral. That would be contrary to that DJ's personal convictions and therefore would raise some suspicions about that DJ's commitment to living for Christ. I am saying that the DJ who is a Christian can play music of any style as long as the lyrical content does not go against the values that we learn in the Bible and our own personal faith an convictions.

I recently did a mixset called "aLife" and for me it was a personal step of growth as an artist and a DJ. It had lyrics that reflected life and all that it entails, from faith to heartbreak. It was dealing with some issues I have dealt with in my own life as a Christian.

So to answer your question, the difference is not in the music, but in the person behind the music.