Here is the full list of all 46 Soundfall trophies - there are 32 bronze, 10 silver, 3 gold and 1 platinum.
You unlocked every trophy in the game
Landed in Symphonia and completed the Tutorial
Complete 25 missions with each hero
Complete all missions in the Skylands
Recruit Jaxon for the team
Grow the team with Lydia
Bring Brite on to the team
Complete the team wth Ky
Defeat 50 Discordians with on-beat attacks
Defeat 100 Discordians with on-beat attacks from Melody's Audio Blade
Obtained the Audio Blade
Break down an equipment item into gold
Use gold to buy an item from the in-game store
Complete all missions in the Beach
Complete all missions in the Forest
Complete all missions in the Volcano
Complete all missions in the Cityscape
Faced Banshee at Harmonia
Complete all missions in the Depths
Complete all missions in the Desert
Complete all missions in the Crypts
Complete all missions in the Jungle
Complete all missions in the Peaks
Defeated Discord and saved Symphonia
Complete all missions on Dangerous Intensity or higher
Complete all missions on Extreme Intensity or higher
Complete all missions on Lethal Intensity
Complete 5 missions on Extreme Intensity or higher
Complete 5 missions on Lethal Intensity
Deal 1000 damage-over-time with Bolero burn
Fully slow 25 Discordians with Serenade freeze
Heal 2000 health using Minuet lifesteal
Hit Discordians 100 times with Requiem chain lightning
Defeat 25 Discordians with Nocturne detonation
Gear up a hero with Legendary items in all equipment slots
Reach Level 50
Complete 20 missions in each environment
Complete 10 missions with 2 or more players
Complete 10 songs using the Free Play menu
Open 100 treasure chests
Defeat 100,000 Discordians
Defeat 5 Discordians with a single shot from Lydia's Audio Bow
Defeat 10 Discordians simultaneously with Jaxon's Stage Dive
Hit 10 Discordians simultaneously with Brite's Area Shield shockwave
Hit 5 Discordians simultaneously with Ky's Scythe Toss
Complete all missions with a Platinum ranking on Lethal Intensity