For a vespers when you would chant the theotokion from the menaion, I’ve heard that you always chant the first one, unless it’s Thursday night, when you would chant the one marked “for the cross”. Is that true, or would you also chant the theotokion for the cross on Tuesday nights?
You chant the “Stavrotheotokion” (or the “Theotokion of the Cross”) on Tuesday and Thursday evenings, as they look to Wednesdays and Fridays – days on which we remember our Lord’s betrayal and crucifixion.
An interesting fact is that these “Stavrotheotokia” in the Cathedral Rite had ornate and melismatic compositions, lasting from 8 to 12 minutes in some cases. The use of the Stavrotheotkia today in the way we use them is a good example of how the Byzantine “synthesis” tried to preserve almost every aspect of both rites, even if they use some of those aspects very differently.