Your question is whether you can utilize your inclination to play the guitar and write songs about Krishna in devotional manner of activity. Several times I have replied this question, I do not know why you are not learning these things. There should be arrangement for distribution of such information to all the devotees if there is some important question, not that I shall have to continue answering over and over the same thing.
But as you have requested, I am your spiritual master, I must reply you to your satisfaction. So this playing guitar and writing of songs is not very important thing. You can write and play, but one cannot take it very seriously. If any Vaisnava is writing song about Krishna, he should have realized himself what is Krishna, just like our great saints and acaryas like Madhvacarya, Ramanujacarya, Rupa Goswami, six Gosvamis, Bilvamangala, Bhaktivinode Thakura, like that. They are self-realized souls, therefore if they write something song about Krishna that will be perfectly from the transcendental platform, without any tinge of mundane influence or nonsense imagination. Unless he comes in the category of these big Vaisnava personalities, his manufacturing some songs will be misleading to himself and to others. And unless his writing of songs can be accepted as gospel, like Vedas, then such writing is simply disturbance and is diverting the attention from the subject matter only. That songs writing we cannot regard very seriously. That will spoil the whole thing. But you can utilize your propensity to write poems and articles for BTG, for singing in the kirtana, like that. That will make you very happy. Now you just apply yourself for becoming qualified to see Krishna face-to-face, then you will be able to actually write songs about Krishna.