How does one distinguish between a proficient musician and a master? The proficient musician possesses all the skills a musician must have - his artistry is impeccable. However, the master possesses something more. The story in the previous post about Alfarabi is an excellent example of the master musician. The master brings new life to music. For the master, the music is merely a means to convey the deepest passional experiences. So how does one become a master? The maqam are the key. They give a student a map (or topology) of the kinds of music appropriate to conveying different psychological states. If the student memorizes these he can simply check his roster for the appropriate maqam for the venue and occasion. This does not automatically make the proficient musician a master. It helps him develop the proper habits of mind.
M'qomot (in the larger sense of the word) are "places" in the imagination (or psyche in modern terminology). They familiarize a student with different situations he might encounter and provide him with a tool-kit of appropriate responses. M'qomot are appropriate to every art which demands a wide range of action from the student. In the case of a musician each maqam gives him a general sense of how to perform. Even if presented with new lyrics or a new composition he can refer back to the appropriate maqam and find guidance. Is this a happy song? a sad song? a somber moment? a festive occasion? a mournful gathering? By training with maqam the musician would rarely feel unprepared. The proficient musician builds his intuition around these maqam. Likewise, the m'qomot of the Ralbag.
Seeing how the mitzvot emerge from the words of the Chumash does not feel natural at first even for an expert reader. The m'qomot are the means to bring new life to that reading - in this case a derekh haChayim.