Great to see so many beginning composers here and being determined to submit to something like this. I pretty much envy what you’ve done. If I had been younger I wouldn’t been able to produce such cool music like you’ve done. You’ve managed to create some pretty atmospheres with a relaxed but interesting texture. While I can commend your work, I do feel like there could be things done differently. So here are some thoughts.
Sad – The D Dorian is an interesting choice. Although I feel like having the A-flat in there makes it a bit to dangerous sounding. Also I feel like the voicing of the strings should vary more. I think it is mostly due to the droning Viola on de A. Changing the drone certainly add some more harmonic richness a give different meaning to the same melody. Also having some instruments not playing like pads might be a great idea to loosen up the sound or give some additional movement. Maybe trying to give one of the strings an ostinato or arpeggio can give more depth
Happy – Really dig the bouncy nature of the groove. I feel like adding some deeper bass playing in some short patterns could enhance that rhythm. Like before I believe adding some variation could be very much benefitting. Maybe change the melody throughout your instruments and let them play different parts. Also a cool Idea is to let them commend each other like a question answer theme (like a group of friends reacting to each other).
Memory – I quite like the idea here. Though I feel like it is the same as beforehand. Though a good Idea it somewhat gets dragged out other the time. Some variation in tone-colour or voicing could help. Maybe, as a simple idea, try going through multiple memories. Maybe some are frightening, some tear driving and some other laughably funny. Let the different emotions drag you and your listener through the song.
Replax – I feel like it could be more of a part of Memory other than being its own thing, Although it has some more movement and evolvement. I do believe that this could use some more ear candy. Some more noises and soundscape the catches the listeners attention and adds to the feeling you’re trying to evoke. Like in Sad it could be also beneficial to add some movement into the instruments by adding some ostinatos or arpeggios to contrast the long padded sounds of the strings.
Though the critique might sound harsh, I really enjoyed listening to your OST. Don’t let yourself get deterred and keep on composing.