I'm really a newbie and self-taught, so I beg your excuses in advance for a poor question. I'm following a course in game programming, and I come out with this progression that IMO should work as a pad for a SCI/FI ambient:
Dm-C-Am-Fsus2/C
The last chord is written that way because it is voiced with C as the bass note. I don't know if it is correct--I hope it is.
The progression first was played with simple triads, and then I decided to add a bass. The bass line was at first D-C-A-F. But this way, the progression "tastes" differently. I tried play it D-C-A-C, where the lower note of last chord is C instead of F. I supposed that the bass should play the tonic of each chord, but it seemed to work better with the lower note (C). Which of these two choices (C or F) is theoretically correct?
Then other question--if I were to write this progression with Roman numerals, since I'm in key of D, I would write: I-VII-V-? What do I put in place of the question mark? How do I show with Roman numerals that I'm using a suspended chord?