Bhagavad Gita is the most famous gita. There are two opinions regarding who spoke Bhagavad Gita, one group says it is Krishna and the others says it is Brahman that Krishna was connected to.
This is justified using this quote from Anugita
परं हि बरह्म कथितं यॊगयुक्तेन तन मया param hi brahma kathitaM yogayuktena tanmayA [Krishna said:]
I discoursed to thee on Supreme Brahma, having concentrated myself in Yoga.(KM Ganguly's translation)
I immersed myself in yoga and told you about the supreme brahman(Bibek Debroy's translation)
There are other gitas like Devi Gita, Ishwara gita etc..
Does the second group believe that it is Brahman connection through Yoga which enabled the respective deities to speak? If yes, does it have scriptural basis like the above one for Krishna? Or the deities themselves speaking here without connection to Brahman through Yoga?
I am not interested in all the gitas, that will make it too broad. Answer can be just for the above gitas that I mentioned.