After going back and forth on this one, I think there are certain DT songs that do fit the overall scheme of Aural Moon. The question shouldn't be "are they too heavy to be prog rock?" since I've noticed an awful lot of heavy stuff on the lists already.
A few DT tracks would be nice if for no other reason than it adds a bit of variety. Someone was asking for specific songs to try, so here's a few of my favs to get you started:
"Learning To Live" - from Images and Words
"The Mirror/Lie" - from Awake (definitely not for AM, though)
"Space-Dye Vest" - from Awake
"A Change Of Seasons" - from A Change of Seasons EP
"Peruvian Skies" - from Falling into Infinity (does get real heavy at the end)
"Trial Of Tears" - from Falling into Infinity
"Finally Free" - from Scenes from a Memory
A few other suggestions that I thought might be worth a listen:
"The Ytse Jam" - from When Dream and Day Unite
"Another Day" - from Images and Words
"Surrounded" - from Images and Words
"Wait For Sleep" - from Images and Words
"Lifting Shadows Off A Dream" - from Awake
"Hollow Years" - from Falling into Infinity
"Take Away My Pain" - from Falling into Infinity
"Beyond This Life" - from Scenes from a Memory
"One Last Time" - from Scenes from a Memory
I'll live whether or not DT is added - there's plenty of bands I haven't heard before on AM already - but I do see the merits of adding one or two songs for the people who haven't heard DT before (and the ones who can't go on without 'em.)
