Psalm singing / seventh of several

The fourth of eight reasons why we should sing the psalms regularly, intentionally and methodically. 

When you sing the psalms you guard against heresy.

[John Calvin]

Andrew Fletcher said, "Let me write a country's songs, and I care not who writes its laws." He was on to something. Songs drive information deep into our hearts. However, this power can be used for ill means. As long as the church has existed, songs have been used to inculcate heresy. There is an assumption that if you can sing it then it must be true. How shall we guard against sung-heresy? Sing psalms.

[I would want a bit more nuance to his suggestion. Yes, let us sing psalms -- and hymns (always using the psalter as our touchstone). To guard against heresy is an ever-present call to diligence.]