To answer this question thoroughly, we would have to enter again into the subject of the RPW and musical instruments in worship...
But think about this: As stated above, the Psalms tell us to sing to the Lord with various instruments; indeed they do. However, the Psalms also speak about tying the sacrifice to the altar and things such as this. Are we bound to do these things as well? No. We know these things have passed away with the ceremonial law, but we still sing these Psalms and we do so in light of what Jesus has done for us.
If interested, I preached a sermon on Psalm 150 that can be found here:
SermonAudio.com - Praise the Lord