I need one week, at least, to learn how to pronunciate this thing.
Why not "obviously"?
That's offenbar, offensichtlich in German.
In this context obviously is synonym of self-evidently, naturally, of course etc. The same may not be true in German of offenbar/offensichtlich (I don't know), but it is in English for obviously, at least in a general sense such as this.
I put obviously and it was accepted.
Can "Selbstverständlich" and "Natürlich" be used interchangeably?
I think that musical instruments require an article "the".
Both "I play guitar" and "I play the guitar" are fine in English and mean the same thing.