thought it would be worthwhile to hear suggestions from others on songs that work well together. ie., one song that transitions well into another because the music (key) and lyrical content are the same/similar.
to get the discussion started, here are two "pairs" that we've used which i'm sure many have heard/used before...
1) How Great Is Our God => How Great Thou Art
coming out of the chorus of HGIOG ("how great, how great, is our God...", right into chorus of HGTA ("then sings my soul...") by putting a passing chord between (i don't have my guitar with me, but i can post the key and transition chord if someone's interested). there is a tempo change, so don't try this on the fly :)
2) How Great Thou Art => I Stand In Awe
from chorus of HGTA ("how great Thou art, how great, Thou art...") => passing chord => chorus of ISIA ("and i stand, i stand, in awe of You..."). again, i throw in a passing chord, which gives everyone the key for the next song, as well as allows me to speak the first few words of "and i stand..." so everyone knows where we're going..