One of the reasons one should learn from a Rebbe and that Torah Shebial Peh must be verbal is the NIGGUN. The written word can't convey the full meaning of the words [even though the Torah's "trop" helps].
Example: The other day I said "[Oh] mannnnnnn". Then I explained to my Israeli daughter that "man" can mean a male or it can have no connection to any man. My daughter told me that she figured it out b/c of the different niggun I use when I refer to the male "man" and the more slangy "man".
