Beautiful. However, while this is within the letter of the law (or minhag), since it’s only vocal, it’s not 100% in the spirit of the law, since the music is on the cheerful side. The Nine Days are a period of mourning, no matter how hard it is for us to remember that. Just like we’re not supposed to make gourmet meatless meals, just plainer foods. We’re like the secular Israeli soldier who was among those who captured the Kosel. It didn’t mean anything to him, but most of the others cried. Eventually, he started to cry, and when asked why, he said that he cried because he w a s n ‘ t crying. What he meant was that he realized that he s h o u l d have felt the need, and he could sense that, but wasn’t able to. אם ירצה ה’ very soon we won’t have to cry and mourn.