Contains very minor spoiler from Call of the Tempestarii
You know that awesome new song from the new quest? Yeah, you can unlock it for your somachord. It's quite simple, I'll show you how.
How to Unlock
First Tone Fragment
The first tone fragment can be found in one of the spy vaults early on in the quest. In my case it was in vault A, but I am guessing that can vary.
Second Tone Fragment
The second tone fragment can be found in the forge room aboard The Flying Dutchm-- err the Tempestarii
And there you have it, easy peasy!