What collection do you mean? If this were the Mahler Concerts this is not a collection, collectios are only for true movie sequels

what is it then, if not a collection? it doesn't make sense to have them all completely seperate because you can only buy them as box set.

If you can only buy them as Box-Set ( what I can't believe because all single concerts you can find in the web) then you have to add them as one movie entry set to Video:true

the audio CDs i found as seperate items, but i cant find the video recordings other than for example https://www.amazon.de/Gustav-Mahler-Sinfonien-Royal-Concertgebouw/dp/B001PARXHW

So I'm deleting the single entries now and as I told you , you can add the DVD Set as one single movvie entry set to video: true

still don't get why tho. its different DVDs with different cast and crew (with overlaps of cause) sold as a set. merging all of that in one entry would just be wrong, wouldn't it?

A DVD Set cannot be a collcetion according to our rules