Helo how to add a B chord, D/E chord when i m in Bb major?

thanks! really not familiar with the section and borrow function. if i can add anything i want would be great.

To get the B chord, go into the “Bor.” drop-down menu and borrow the ♭II chord from Phrygian. (It’s spelled as C♭, not B, but it’s the same thing.)

You can get D/E by clicking “V of,” checking the 11 box, and choosing the V¹¹/vii chord. If you just want Hookpad to play that chord, that’s the easiest way, but if you’re wanting to analyze a song and the “V of” spelling doesn’t apply (i.e., the next chord after it isn’t “vii”), you can get the chord in its regular form by switching the whole tab’s mode to minor, going into the “Bor.” menu and clicking Major, checking the 11 box, picking #vi¹¹, then switching the tab back to major.

When I change the song’s key from major to minor to select the chord I want and then change the song’s key back to major, the chord has changed to something different. How do I modulate only a section of a song to a different key?

You have to change the Hookpad settings to use relative transpositions for mode changes first. (The new default functionality of parallel transposition was only added a few days ago which is why jtullis’s instructions don’t mention changing the setting.)