I am reading over a score that begins with some sort of chord. The notes are (all concert notes): Bb, C, A, G, D, F, E, Eb. The piece is in Eb Major I believe. I would like to know both what the chord is and how to determine it. The name of the piece is O Magnum Mysterium transcribed for band by H. Robert Reynolds. Thanks in advance
You wrote that the score is for band.
Could the notes you're citing come from parts from transposing instruments like clarinet, trumpet etc? Those staffs are generally denoted in a different key than the non-transposing instruments (i.e. flute). This is important, because the transposing instruments will sound differently than their notated notes.
From what I can tell this "O Magnam Mysterium" is orignally a choir work by Lauridsen in D, which starts with a 1st inversion of the D9 major chord (first degree of the scale, F, D, E, A). The band score is transposed to Eb, so it would be G, Eb, F, Bb.
To determine what any chord is, you should just look at all of the notes played and see what chords they match up to. For a piece in Eb Major, you would start seeing if the chords match Eb Major, or its fifth, Bb Major, or its seventh (as it's a jazz piece) Db Major.
For a chord like this, if you just list them in order starting on C, you get C, D, Eb, E, F, G, Bb. It's almost a complete scale. Which means it doesn't really match up to any conventional 'chord' you may be looking for, with the exception of some very obscure ones that mean very little.
My advice: don't try to label it. Not everything is a happy chord.