Thank you for explaining,
Anyway, I recommend you to download
2i2 Gen4 Manual before you buy and see chapter
Examples of use (p.34 and especially p.35). As you can see, 2i2 has only two inputs. That means, if you connect keyboard to it (as stereo device), then you can't additionally connect a microphone. That's ok, if you plan to have microphone connected to keyboard (as you probably have now), because in this case microphone is automatically mixed into stereo signal. However, I think that's a lot of money for only being able to control loudness of external speakers.
Because it just came to market, I can see that 4th Scarlett generation is quite expensive compared to previous 3rd Gen. What I'm suggesting is, to consider Scarlett
4i4 Gen3, which you can still get for almost the same money -and it has four inputs!
By having four inputs, you can connect a keyboard and up to two microphones. But what's important to know is, each input is recorded as separate device. That is, it can never happen that your singing will be too loud or too quiet compared to keyboard -because you can adjust levels on PC later at mixing final result.
Ok, maybe you don't need that feature right now, but as said, is almost the same money...
Bogdan
