The Gemara says that learning without song is called: חוּםיִבוֹט אֹל םיִקּ “laws that are no good”. Dovid wanted his Tehilim to be as Chashuv as Nega’im and Ohalos (the deepest topics of Torah) and he once said: יִל וּיָה תוֹרִמְז ˃יֶקֻּח תהלים קיט נד Your commandments are to me like a song. The Gemara says that that Dovid HaMelech learned Torah the first half of the night, and the other half he sang praises to Hashem. R’ Zundel of Salant Zatzal explains that he sang in appreciation and Simcha over the Torah that he had just learned.
Perhaps this is why he was so against Doeg HaEdomi, despite his being a major Talmid Chochom. The name Doeg means “worry”, and we can suggest that Dovid wasn’t Machshiv the Torah of Doeg HaEdomi since it was devoid of Zemiros. (A worrier doesn’t sing so fast and without: ִסיפּוּ ַה ק ֶנ ֶפשׁ satisfaction in life, people do evil).
