Out of the available instruments in the area, you decided that you should play the guitar in order to get the door open, but before you begin to play the guitar, you make sure that it's plugged in despite the high possibility that there isn't any power in the building due to the apocalypse as a whole. However, you are left completely baffled when the guitar receives power. Now, normally you'd be put off by the power present in the building and its outlets, but you deduce that it could be coming from a backup generator, which lessens your worries. Anyways, now that your guitar has some power, you take it off of the stand and begin to play it. However, something strange happens once you start playing; you're actually playing the guitar very well.... unnaturally well. Hell, this is actually the first time that you've played the guitar, which makes this even stranger. However, you playing the guitair well, isn't the strangest thing here, because you are changing, both physically and mentally without you even realizing it...
Your transformation begins with your height as you shrink all the way down to the average height of an inkling woman. This is followed by your figure changing to a proper hourglass esc shape that your new fans will surely love. The next parts of you to change are your skin, and your facial features. Starting off with your skin, it becomes soft to the touch while feeling a bit like silk. As for your facial features they become more feminine while a line forms between your eyes, similar to that of an actual inkling. After this, some of your body fat moves in two different directions. The firs of these groups heads to your upper chest, expanding outwards and forming B cup breasts in the process. As for the second group, it heads down to your rear and expands it to a decent size. Heck it's even a bit bouncy too, which is even better. Next, your ears expand outwards a bit before becoming pointed, which is a pretty notable trait of the inkling species. After this, your hair begins to grow into two different shapes and lengths. On your left your hair greatly lengthens while not really going into any specific shapes. Your right on the other hand doesn't really grow all that much. However, it ties up into a beautiful side braid that'll surely arouse all of your cephalopod fans. Shortly after your hair elongates and shapes itself, it turns into some sexy and smooth purple inkling tentacles that your fans absolutely adore. Finally your penis and testicles go into your body and change their shape into ovaries and quite the attractive vagina...
Shortly after this final physical change occurs, you feel your mind becoming incredibly fuzzy, as your old memories get replaced by new ones of a very successful female inkling guitarist, and shortly after this you begin to speak with your new feminine voice as you end your rehearsal...
"Woomy, looks like my guitar skills are as sharp as ever, great! My fans are going to love my new guitar single, I just know it!," you say to yourself as the PA system announces, "Rehearsal Over, doors to the main stage have been unlocked." You then respond to this stating, "Well, I shouldn't keep my fans waiting, I better get to the stage." You then proceed to head through the doors; performing your new single to your excited crowd of female cephalopod fans shortly afterwards.