Is the good music we hear on earth anything like the music of heaven?
Yes. Good music heard on earth is only a sampling of what believers will experience in glory. Heaven possesses beauty and music, and Paul was given a glimpse of paradise. The magnificent realities he saw and heard were unspeakable, so earthly music merely hints at the music of heaven.
Les explains that Paul had now gotten a glimpse of heaven as we normally think of it, with all its beauty, and no doubt with all of its music. Because he loves music, Les believes that when we hear good music down below, it is just a sampling of what we are going to experience when we get to glory. Paul evidently had a full exposure to all this: he saw the glories, heard the magnificent things, and was caught up into paradise, where he heard unspeakable words that were not permitted or lawful for a man to utter. God allowed Paul to see and hear but told him he could not repeat it, so he had to keep it to himself. Thus earthly good music is only a foretaste of the music and glory of heaven.