Next, flip the matrix over so that the slots running perpendicular to the strands are on top. Wiring up the rows is a bit trickier, because we're working in close quarters. However, unlike the columns, the rows need only 1 wire per LED, a total of 49 wires. Here's where the slack we created by using 4" long wires comes in handy. It lets us manipulate the LED's more easily. Connect the anodes with 6" lengths of wire. The yellow wires in my photo are the anode connections. I had an old spool of yellow wire, but it ran out before I was done with the rows. It's easier to wire up all the anodes before you insert the LED's into the slits, as pictured.