three "groups of musicians"

What should replace the question mark? Explain why.

If,

   001 111 100  |   |   |   |  |   |   |   | = 2:3  |   |   |   |   010 111 100  |   |   |   |  |   |   |   | = 2:3  |   |   |   |   100 111 100  |   |   |   |  |   |   |   | = 2:3  |   |   |   |

Then,

   000 110 100  |   |   |   |  |   |   |   | = ?  |   |   |   |