The very important family of metabricks, "To IV n Back", is introduced in Part I of this two-part podcast. The harmonic purpose of the family is introduced and then focus is given to the most common form: the "To IV n Yak". This metabrick is made up of On + (Boostrap) Cadence + (New Horizon) Yardbird Cadence. Many examples from real songs are shown to illustrate just how common this harmonic move is. Passing reference is made to the related "To IV n Mack" and also the "Pennies Ending" metabricks. Chaining of more than one "To IV n Back" is illustrated with reference to real standards. Modulation in major harmony via dominant 7th chords with roots other than V is discussed and the reason why modulating to IV does not feel as strong as modulation to other places.