That completely ignores arrangements, timbre, etc. It also ignores the fact that music isn't received in a vacuum - our responses are at least to some extent taught. If I hear a progression or even an arrangement that's similar to something I know, and which I already have formed some reaction to, then this will influence how I respond to the new music.
Stuff like Mogwai makes me react with mild boredom and frustration, sometimes punctuated by rolling my eyes at how tedious it is. I'm not writing this to be a hater, but to demonstrate that your theory doesn't actually hold in practice.
I wasnt trying to get in depth, merely show that intrumental music, generally, operates on moving people through musical 'laws', certain notes will sound sad (for whatever reason, we'l talk about that later). If we are talking about opinions take it as a song, it can sound similar to, but not the same as a song, theres a racer X solo thats alot like a rage against the machine solo, difference? Minor third. While when listening to either I'm reminded of the other song it doesnt change the fact RATM is sadder than Racer X, because of the minor third.
As far as emotional response due to some kind of osmosis from other songs, or memories; I have no idea. Thats not an area of music and psychology i know anything about and wasnt really what I was getting at, good point and well made, food for thought.
In refernce to mogwai, it doesn't matter so much as whether anything enthralls you, a song written in a certain way, whether you like it or not will sound sad. You cannot argue minor music sounds joyous, neither can you argue a full orchestra reaching crescendo after a major fugue sounds sad. Thats how it is.
The real question is whether or not the emotional reaction to harmony is 'hard wired' or socialised? I've always assumed that it's the former, but that's just fucked up and really I can't get my head around it. Do we associate a minor key with sadness because it is 'inherently' sad, or is it because it's been used in the past to represent sadness? I guess if it's the latter then it's similar to language - I mean, it seems intuitive that a minor key is sad, but it also seems intuitive that the sound 'dog' represents a dog (or the conceptual signified that corresponds to whatever it is a 'real' dog is, to adopt Saussure's terminology, but let's not get too technical).
I mean, a minor triad is made up of the same elements of a major triad (if you look at it one way) - a minor third and a major third; it's just that in a major chord the major third is below the minor third, and in a minor chord it's the other way around. Why the hell should this be 'sad' or 'happy'?
Music is insane if you think about it. How does it even WORK.
I'd disagree that its socialised, its not as if people when we were Labelling and writing the mechanics of music decied; 'this note is sad'. During the Baroque era when alot of modern music theory was founded, emotional responses (or even names) were based on traditions, sad songs had a minor 3rd and a raised 7th, for example. HOWEVER the this is not a fact that pertains to that era, or time or culture, or geography, the exact same things happen all over the world and those musical events that are called minor will ALWAYS sound sad, no matter whether your 5th mutist or a 21st century harpsichordist, Western Classical composer or Arabic cleric.
In regards to how does music work, it just does. Dont try to look into it as brain waves adn psychological responses, you'll die of confusion (and it makes music alot less fun). Eventually it gets to the point were almost every note can sound right, because, if you know how, you can manipulate the music to suit you (in the sense of adding diminsihed, augmented, suspended coloured notes to a chord, as well as infite other manipulations). That being said, in order not to contradict myself, thats another dimension upon a basic 'sad' or 'happy' note. Its creating another level to that chord, they'll still be sad or happy (assuming we are ONLY sticking to minor and majors here) but prehaps more melencolic, or more climactical.