Music is structured abstract, i.e. There is a boundary for us (set of of rules) but within that we can work according to our level of imagination, experience and training. One can’t predict that a concert that is yet to happen will be excellent. In a performance sometimes you can sense that the artiste is in a good mood and is singing well. Contrary to this he can perform average and an artiste can never guarantee a performance. Thus the benchmark of a great artiste is that he consistently delivers high quality performances, their percentage of average performances will be very low.
Enjoyment, a central point is the basic requirement in music. Music and enjoyment go hand in hand. We have heard incidences of amazing musical effects like starting Rain, Anandashru (tears of joy), when swami vivekanandji use to sing Sri Ramakrishna Paramahamsa was attaining bhava Samadhi.
The audience can’t enjoy music unless and until the performer himself enjoys it. As a very famous drama artiste Master Hiranaih once told, ‘if you have lot of sweets, you can feed others’. A musician enjoys every aalap, every note, every piece of tabla bols he sings and plays. I used to sit with guruji for his concerts, I used to wonder at times see guruji saying ‘wah’ and ‘kya bath hai’ for tabla bol or a good harmonium support. Later I realized that it comes naturally from the bliss of sheer enjoyment. A listener enjoys an artistes work by experiencing “his work under progression”. A work is going on in ane raga and you enjoy that. For example, Leh-Laddhak is very beautiful place in India. We can see pictures or video of that place or narration of that place by friend and we can enjoy. You personally go there and experience the beauty of nature it is completely different. This is how an artiste and a listener enjoy music. Artiste visits that place and enjoy and listener enjoy in a different realm.