OH Beat is an expressive way to show immediate or postponed shock to a normal, outrageous, or obsene idea, response or sight. It is comparable to other commonly used phrases such as " OH my gosh "or "WTF".
There are a variety or ways to use this phrase.
There is the classic OH beat with emphasis put on the O.
There is the silent OH beat where the phrase is simply mouthed.
There is the musical OH beat where you repeat the phrase in a kind of sing along.
There is the repeat OH Beat which is said in a rapid fire manner until the extent of shock is conveyed.