Here are some quick Pick-and-Choose Valentines Music Ideas:

Pick songs out of:  Empty candy boxes or conversation heart party favors.

Have the letters K I S S E S scattered across the room.  Let the children find them one at a time and sing a song for each letter.  See if they can spell the word.

Here's an idea that's not quite as easy but I might attempt it this week:
Get a big piece of white butcher paper and draw a big heart on it (just the outline of a heart).  Hang the paper on the chalkboard.  As the children sing a song, pick 2 or 3 kids to come up and draw a valentine's picture inside the heart (or just color in it).  At the end of Singing time, write We Love Our Bishop!!! and give it to your Bishop to hang in his office.