Intervals. We know 'em when we hear 'em, right? Can you sing one when you're asked? Can you read it in music? Intervals (which lead to scales and key signatures) are some of the toughest concepts for young musicians to learn, especially singers. But, all musicians must know their intervals -- the measured distances between individual notes. Knowing intervals helps you read music faster and more accurately. Pianists can press a couple of keys, brass players can press a valve or two, and the result will usually be the same each time. Singers learn intervals by feeling the resonance in their heads and throats, while listening to the sound that come out of their mouths -- and that can mean endless variety of pitch. A tuner can help singers identify intervals before they begin to associate them with a "feeling" in their own bodies.

Music teachers always use common melodies to teach intervals; for instance, the perfect fourth interval sounds just like the beginning of "Here Comes The Bride," and the opening notes of "Somewhere Over The Rainbow" comprise an octave. Other intervals are harder to quickly identify in music because  . . . they sound weird, they aren't used in music that people can recall instantly, or they're hard to sing. To the rescue, a few YouTube videos that I found helpful:

1.  "The Interval Song," a Latin-beat ditty by a British composer named Django Bates. May also make a good drinking game for college theory students. Sing it a few times and you will know it forever.

2. "Interval Song" by Anonymous. I have never heard this one before but the song and the performer are both really cute. I like any song that attempts to rhyme "octave" and "provocative."

3. "Intervals In Inversion Song," by David Newman. I'd like to hand this guy a rose for coming up with this hilarious song. I love the wonderfully sappy piano accompaniment.

4. For kinesthetic and visual learners, check out Leonard Bernstein's "Young People's Concerts," which devotes an entire hour to intervals called  "Musical Atoms." Might be interval overkill for some, but if you're at all interested, it's an hour well spent.

Do intervals really matter? Ask him.