So what is the key to writing great music? E minor? Just kidding......
I mean what characteristics should a good song possess in your opinion?

For me it should contain

- Meaningful lyrics
- A "Soulful Solo"

etc...... :/

Any kind of song can be great music. There is no set list of things that great music should include.
It has to be great. If there were a formula for it anyone could write great music.
I have the belief that somewhere on earth, there is an astronomically large list of all things that make great songs. But get this, only a select number people get to few this list every month of every year and take 10 ideas from said list...

Prove me wrong.
What if a song doesn't have a "soulful solo?"
^^The above is a Cryptic Metaphor^^

"To know the truth of history is to realize its ultimate myth and its inevitable ambiguity." Everything is made up and the facts don't matter.

I'm of the opinion that there are two fundamental aspects to a song that will make it great. The first is rhythm, and the second is harmony/melody. While I haven't studied rhythm in depth, I can tell you that the danceability of a song is important, although not absolutely crucial. There are, after all, many great songs that you wouldn't necessarily dance to. However, the ability of rhythm to improve a song is well-tested. The feeling generated by a rockabilly or punk song suddenly going into doubletime is one example of this, as is the wide success of the band Santana, which put significant emphasis on rhythm. However, because rhythm to me seems to boil down to the simple equation of "pounding drums at steady tempo = people dancing," I'm more inclined to study the intricacies of harmony/melody to find an equation for great songs. On that note, I'll just say that the key to great harmony/melody is to know the major scale in and out, how it's harmonized, how chords tend to want to move within it, and how a melody wants to resolve to a chord. Although this seems like a lifelong pursuit, it's fairly basic math: chords form a major, minor, or diminished triad; voices like to move in small steps, sometimes chromatically; the human ear hates dissonant intervals; melodies like to resolve to octaves, thirds, and fifths, etc etc. Once these principles are applied, you should be able to construct a very listenable song without too much trouble. In fact, some songs have managed to become classics using these principles alone and nothing else. There is something wonderful about a very simple melody over a very simple chord progression, as can be seen with songs like Auld Lang Syne, Amazing Grace, Hey Jude, etc. I tend to think that these simple songs have become cherished due to their tendency to make people want to sing in a group, which seems to make people feel better than songs that are sung by just one person. There is also something to be said for a song's familiarity and exposure within a culture, which explains why some melodies are more memorable than others, even though they both seem to follow roughly the same patterns and principles.

However (and this is the part you've been waiting for), it is my honest opinion that the key to writing a great song is to take the very stable, mathematical, ear-pleasing rules of harmony and tweak them a bit to create tension and variety. Perhaps the best example of this the Harmonic Minor scale, which has long been accepted within the world of classical music. The use of a semitone resolution from the 7 to the 1 of a scale allows for more tension within chord progression, as can be seen with the V7 - i cadence. Other examples of this include the IV-iv-I resolution, which is very interesting to the virgin ear (although those who have been exposed to it many times will eventually expect it and lose interest, unfortunately). Perhaps the most famous device for creating tension and stepping outside key is the "half-step key jump" that comes near the end of some pop songs as the chorus is repeated. It creates tension and then quickly resolves it as the same harmony and melody is repeated in the new key. There are many methods like this, and the best way to find them is to listen to a wide variety of music. I'm a jazz fan myself, so I'm biased, but I can tell you that old swing standards make use of many more tension-creating tricks than modern songs, so that's a good place to start.
Anyway, the point here is that although there are many traditional melodies and chord progressions that can create catchy songs, all of them have been used over and over again to the point that they're completely predictable and stale. The way to write Great music, which is the conversation we're having here, is to experiment with bending the rules of harmony a bit until you strike something that's both unpredictable and listenable. That's how you catch people's attention and make them remember a song. That, or shoot a really risque music video.
How do you quantify that?

I mean that's as useful as saying "Oh the key to that is writing a great song". It's mindless and accomplishes nothing. How do you quantify "a great song"?

Meaningful lyrics? Really? So a meaningful lyric means a lyric that has meaning.

Soulful solo? What's that really? How do you quantify that?

This is the epitome of futility.


I was going to come in here and say f11... like the button...

But its a different kind of thread...
Understand nothing, in order to learn everything.

Quote by liampje
I can write a coherent tune ... But 3/4? I play rock, not polka.
Best thing to do is to write down a list of what you like and base it off that...

3 things for me that really stand out are:

1. How good your intro is
2. How catchy the chorus is
3. Rhythm (i.e. American Idiot comes to mind; "4 chord-ish" song but unique rhythm)

Obviously easier said than done...
Quote by Basti95
It has to be great. If there were a formula for it anyone could write great music.

Who says anyone can't? Maybe anyone can and they just never figured out the technique to.
Music is incredily subjective, so asking in a forum probably won't warrent a successful response. I understand your seeking for the perfect "formula", though.

For me, it's more about the music than lyrics. They're just (sometimes) icing on the musical cake. I understand what you mean by "soulful solo", which, I think, is why I'm so attracted to Pink Floyd. Gilmour has countless solos that strike me as having more "feeling" than most.

Also, coming up with a particularly interesting and unique key/rhythm combination is a bonus.

Just my two cents, anyhow.
Quote by Trowzaa
I wish I was American.

~ A Rolling Potato Gathers No Moss ~