When you tune a guitar, the most important thing is not the absolute pitch of the strings but their relation to each other. So you hold the fifth fret of the lowest string, and then pluck the next-highest string. The two notes should be the same. Then you do the same for the next-highest string and the next-next highest, and so forth. Eventually, the whole guitar is in tune with itself, each string vibrating in harmonic proportion to the next. At that point lives in the guitar the potential for all the music that exists in the universe.
Sometimes, though, when you're tuning, it doesn't quite work out. The top string doesn't match the bottom string, so you twiddle the knob. Then it's higher, so you twiddle the knob back again. Then it's lower. Twiddle, twiddle. At a certain point you've scrutinized the sounds so many times you're not even sure which string is higher or lower, you just know that they're different. It's as though some combination of heat, humidity, and sheer molecular dissatisfaction is making that tuning knob slither back and forth defiantly past its sweet spot.
Eventually, perhaps, you give up, do your best, and move on to the next string. But now the guitar is out of tune and all your little mistakes snowball, the strings' vibrations careening around like balls on a pool table, and a hesitant strum across the belly of the instrument yields a jangly caterwaul, as if you were scraping your fingernails across a dying cat.
Human moods are a bit like that. After being played for a while - or, simply sitting still through the changing weather - all our little tuning knobs slip to one side or the other, and we begin to jangle. At that point, if we want to make any music at all, it's necessary to take a little time and get back into tune. If our tuning knobs are a bit sticky, perhaps it's necessary to remove them, clean them, and put the instrument back together. This may be quite time consuming, but what's the alternative, if we want music and not a jangle?
Hatha yoga is one of the most effective ways I've found so far to tune a human guitar. Of course, sometimes physical yoga isn't what's called for. The best tuning method may instead be sitting meditation, mantra chanting, a hot bath, a nourishing meal, a clarifying conversation with a loved one, the fulfillment of a procrastinated-on duty, or perhaps a stroll through a cemetary. Whatever shape it takes, though, this tuning process is one of the most important things we can learn as human beings, to live our lives melodiously.
I went to an Indian sitar concert where the instruments were so delicate, subtle, and finely pitched that the musicians re-tuned them in between each half-hour raga. But these sitars were just made of wood, glue and string. Our human instruments are made of body, mind, and spirit. Is our tuning any less important, for the kind of music we'd like to play?