What does 'selah' mean?

The word 'selah' appears frequently in the Psalms (4: 2, 4; 7; 5; 9: 16 etc.) When the psalm is read, this word need not be read as it is only a musical notation intended to give direction to the singers of the Hebrew psaltery. It is a liturgical or musical direction probably given by the leader of the Choir to raise to the voice or perhaps to indicate a pause. Scholars are not agreed to the literal meaning of it. The word appears outside the Psalter also: (See Heb. 3: 3, 9, 13). It does not appear in any of the prose narratives in the Bible. Even if we put the psalm into music, the word 'selah" need not be taken into the new musical notations as its real meaning and relevance is not yet clear from the various contexts in which it is found.