A discussion via IM with our buddy Cassanova has prompted me to be aware that the concept of "interval" is a topic which needs to be explained for at least some of our members. I will attempt to do so, as clearly and informatively as possible for my limited communication skills: For our purposes, we will work with the key of C major, mainly because it has no sharps or flats to bother us (because in addition to being in possession of poor communication skills, I'm also lazy ). There are two important pieces of information when describing an interval: I call one the "quantity", or the rough distance between the 2 notes (which I will underline); the other I call "quality", the exact distance. Hopefully all this will make some sense to someone... 2nds: minor2 BC, EF major2 AB, CD, DE, FG, GA 3rds: minor3 AC, BD, DF, EG major3 CE, FA, GB 4ths: perfect4 AD, BE, CF, DG, EA, GC augmented4 FB 5ths: diminished5 BF perfect5 AE, CG, DA, EB, FC, GD 6ths: minor6 AF, BG, EC major6 CE, DB, FD, GE 7ths: minor7 AG, BA, DC, ED, GF major7 CB, FE Octave perfect oct. each note to the next appearance of that note (i.e. C to C1) Now, a couple of things to notice: In each "Quantity" group, there are 7 total pairs of notes, while the number of "Quality" varies. Some "Qualities" are referred to as major/minor, some as perfect/augmented-diminished. There is a historical reason for this difference, which we will not go into here, as it's beyond the goal of this post. Just consider it like a theorem in mathematics, it just "is" for our present purposes. I didn't specify the distance between each interval in whole/half step distances, but that information is simple enough to discover for yourself, and worth the effort to discover (i.e. B to C is a half step, C to B is five and one half steps). Once you "know" a certain interval from this post, you "know" many others: An explaination - C to E is a major 3rd, then C to Eb is what? A minor 3rd. The same is true for C# to E, it's "smaller" than C to E, therefore it's a minor 3rd. Conversely, E to C is a minor 6th, then E to C# would be a major 6th. I'm certain that this will bring as many questions to people as it will answers, and of course any additional input from other members would be greatly appreciated! If you don't get something, ask, and someone will pitch in to help out, based on past experience - either myself or someone else with as much or more knowledge in this field.