Today, of course, when numbers matter, we might be tempted to say that small groups do not really count. The rabbis said, however, that though the Levites were the smallest in number they were closest to the glory of God (Midrash Tanchuma).
Why did they merit this distinction?
There are many possible answers. One with special appeal is that the Levites were the singers. It is they who made up the sanctuary choir. Theirs was the privilege of putting words into song. Their song took wings and reached the heavenly throne, there to join the angelic choir with its kadosh, kadosh, kadosh.
Their example is the model which has always been the inspiration of cantors and synagogue choirs.
Not that cantors always reached the ideal, and many were criticised for placing showmanship before devotion. Nor did choristers always understand that their task was not to perform but to give a lead and shape to congregational song. But at times it was said that the best of cantors reached greater spiritual heights with his singing that did rabbis with their exegesis and expositions.
This is not an argument against rabbis, but an expression of the significance of song in the synagogue and in Jewish life.