I don't think this is a binary issue i.e. it is not either: (i) "hum it" or (ii) "know the scale patterns".

I think one complements the other and it is ultimately self defeating to try and do one with out the other !

I want to travel to Newcastle from Iowa.

Do I have to use only one mode of transport to get there ?
No !

I can use the train and the plain and even the automobile !