Intervals Without Establishing a Key

[rs555]

I make a serious effort to sing and memorize the sound of intervals and the sound of the relationship of each note to the tonic of an established key. Often, when I don't establish a key, it's difficult to recall certain intervals out of thin air. For example, a M3 is immediate to me within an established key, but it's more elusive if I were to just decide to sing a M3 down from any given note with no prior established key. Inversely, it can be difficult to recall specific intervals when I have established a key and my ear is pulled to a diatonic scale.

I'm just curious if anyone else has the problem of getting "stuck" in a key when trying to mentally produce certain intervals, and if the value is worth the effort of being able to immediately recall any and all intervals without having established some kind harmonic framework.

Thanks for the replies.