This week’s guest on the Weekly Interval is the ascending sharped 4th, also known as the infamousTri-Tone. It’s called the Tri-Tone because the distance between the two notes of this interval is three (tri) whole tones. It’s also the interval which marks the halfway point of our trip up the scale. Play the interval. Listen to it. The Tri-Tone has a lot of tension. As you may remember from previous posts, it is the tension of the two notes of the Tri-Tone that are at the core of the Dominant 7th Chord. Remember to spend a week with this interval, play it in different keys, and listen for the melodies of familiar songs to jump out as you practice listening to the Tri-Tone. If you do hear the melody to a song that starts with this interval other than those listed below post it in the comments section.