This is a form of divination meant to be done by a musician and performer who can sing (and ideally play an instrument for accompaniment, but if you're a good enough singer, that may not matter). To do this, you will need a sortilege method of divination, a whole lot of memorized songs, and your own talents.

A sortilege method of divination is any one where there are a number of random components and something is done to them to put them in a random order and then interpret them. For example, Tarot is a sortilege method, as is runes and divination via playing cards, dice, etc. Northern Paganism aside, if you use the Tarot, that will work well as your sortilege method. Pick your favorite deck, go through it, and list two songs for each of the cards - one for the upright meaning and one for the reversed meaning. They do not have to illustrate the song in any way that is apparent to anyone listening; it need only have meaning for you. That's 156 songs, which is a respectable number.

If you prefer something more Northern Tradition, I sugest putting together a bag of stones. 24 or 33 of them can be runes, depending on whether you use the Futhark or Futhorc, but that's really not enough songs for a properly varied bardic divination repertoire. I might suggest adding nine stones for the nine worlds, four for the four dwarves of the four directions, one for the Tree, one for the Ancestors, and one for the Sun and Moon. After that you could add stones for Gods, for spiritual/mythic creatures, or anything else that seems right. You want to have more than a hundred sortilege pieces - and yes, that means that you'll be learning more than a hundred songs. The more, the better. Pick meaningful songs, ones that will make sense to the audience. Pick songs about the human condition, especially. It's perfectly all right to pick pop or rock songs - my own bardic divination kit contains Beatles, Indigo Girls, and Don Henley among other things. There's a wealth of songs about people's experiences out there waiting to be used. I eventually compiled mine into a booklet and printed it, in case I forget either the words to any of them or which songs go to what sortilege piece.

Then you go to a group event and announce that you will be doing bardic divination. Ground and center yourself first, because you are going to be a vessel for the Gods to work through. One at a time, have people pull a card or take a stone or whatever method you are using. As they select, explain that you are not going to interpret the song that the Gods choose for them. It's between them and the Gods, a special message. I even prefer to use a Tarot deck where the symbolism is not obvious to the onlooker, and/or not to tell them that the stone they chose is Niflheim. The divination is entirely in the songs; the sortilege is just the way the Gods communicate the message to you, the bardic diviner. Sing them their song. Don't be alarmed if they become emotional. Don't explain it or talk about it; let them go off and talk to the Gods and figure it out for themselves.

Then take another volunteer. I'm never short of people wanting to participate; usually my voice wears out before the line stops, and I have to decline the rest. Which is why it's good to say up front that this is first-come-first-serve. You may find yourself oddly trancing while singing your songs; that's not unusual. It's the Gods working through you, playing you like an instrument. Be their instrument. This is an honor.