Blending chords not in the same key/scale....

Harmony is a complex topic, so short answers will barely scratch the surface. But in general, the chords that sound good are doing one of three things:

1. They really are in the key, but you aren't identifying the key correctly. You were told that the first chord is the key, and that could be the problem - because it's not accurate. Probably half the music out there doesn't start with the "tonic" (key) chord. And if you're in a minor key, there are lots of different types of minor scales... and each scale harmonizes to produce different chords. Sometimes chords that look like they're outside the key really aren't - the music is just harmonizing from a different scale than the one you have in mind.

2. The music could be "modulating", which means it changes keys. Modulations have been used for hundreds of years to keep things interesting. Sometimes modulations are really clear - there are key changes marked in the music (in standard notation), but most of the time they're not. And in some styles, like jazz, you can be changing keys frequently - sometimes as often as every couple of beats!

3. "Outside" chords (as in 'outside the key') are often used for effect. Listen to a tune like "Stormy Monday" and you'll hear an outside chord that slides down a half step to become a chord that's in the key. This kind of thing is also pretty common.

On top of that, not all songs follow the 'rules' - sometimes deliberately, sometimes out of ignorance (many songwriters have no real music training). And that's ok - if it sounds good, it's right. Music theory adapts as musicians try stuff that hasn't been done before.

Thanks so much, It's good to hear someone say if it sounds good it's OK.

If you don't mind me asking, when I do have a progression that uses chords that aren't a part of any scale I can recognise how do I go about designing a solo for that progression?

Thanks again.

If the chords are just decorations - like the chromatic ones in "Stormy Monday" you can simply ignore them, and use whatever scale works over the rest of the progression.

But if they're part of a modulation, you'll have to identify the new key, and use a different scale at that point.

I'd suggest you read up a bit on music theory - there are lessons on here, including one I wrote on how chord progressions work. Once you can identify the actual keys - and hear where they change - you'll be in a better position to decide what scales to use.

Thanks mate will do :)