IMHO:
There seems to be widely differing opinions on this subject. Aside from the lyrics the music is an issue, but not addressed by the Bible. Thus personal taste is involved (beauty is in the ear of the hearer, like beauty in the eye of the beholder).
Apparently many do not agree with me, as it seems that some continue to sing worn out hymns from the old fogey hymnal, though I enjoy the best of the old hymns.
And many seem to like what I call recitatif songs, songs that have flat melody, not going much up or down (boring to me). It seems to me that many such songs have been & are being churned out, songs that have very good words of praise, but just no beauty to the tune, being little more than a chant. Yet some must like these, as song leaders seem to be picking them for the praise service.
I like some of the classical oratorios (Messiah, Elijah, etc.). But my favorite is contemporary Christian music when the tune is beautiful, the words praise the Lord, the words fit the meter (not crammed over the tune), and the words rhyme.
My pet peeve is excessive loudness, that is, electronically amplified loudness to the point of damaging ears physically -- also drums that are too loud. I carry ear plugs with me to church singing events just in case they are needed.