Another small piece for analysis

[rbarata]

Hello

This one I called it "Tapping" because it's very easy to play it that way.

tapping.pdf

I made its analysis and some questions came up.

In my view this is a piece in the key of BMaj and the chords BMaj and BMaj7, EMaj and F#Maj are the I, IV and V, respectively. So we have a progression like this:

I-IV-I-V-I

My questions are related with the chords "in between":

B7, Em, Bm and F#Maj7

I tried to find how did they appeared in this progression:

B7 - It can be see as the V of EMaj or borrowed from B Mixolydian

Em - It can be see as borrowed from the E natural minor scale or from E Phrygian or E Dorian.

Bm - Can be borrowed from B nat. minor or from B Dorian or Phrygian.

F#Maj7 - I see it as a 2nd inversion of the F#Maj7

Apart from the above, what is the "criteria" to say that one chord has a determined origin when it has several possible?

[walternewton]

Is choosing an appropriate key signature really beyond the capabilities of your software??? - it should be a simple setting...

[rbarata]

Hello walter

I choosed deliberately not to use a key signature. It helps me keep tracking of all the accidentals in the staff while it's still possible for others to understand what's in there.