When you go to learn a song, you should first listen and figure out the pattern. The pattern is the order of the chord progressions being played. The key is to follow your bass line, then you will know exactly what progression(s) to use. What you do is write down the bass notes, figure out what key you are in, then translate those bass notes into numbers. Those numbers will represent your scale degrees for the key you are in. Once you have your progression pattern(s) and your key, then you can put chords with those bass notes. The chords can the ones you figure out from the CD, or they can be your own chords that you want to use. Here is an example:
Bass notes = D-G-C-F-Bb-Eb
Key = Eb
Bass notes in # form: 7-3-6-2-5-1 (this is your progression pattern)
So, let's put chords with those bass notes:
Key Eb LH/RH
D / A-C-E-G
G / B-Eb-F-Bb
C / Bb-D-Eb-G
F / D-G-B
Bb / Eb-Ab-C
Eb / F-G-Bb-Eb
That's basically what you should do when learning a song. If you take a look at all the progressions posts I have done, I have tried to list the most familiar progressions found in most gospel music. So, what you have to do is practice those progressions, then listen to CD's to see if you can spot them when you hear them. It will take a while to get used to this, but it will save you $100s of dollars on buying sheet music. Trust me, I know from personal experience!!!