Dear Natsarun:
I recieved your email. So far I'm alright to teach the class. I will do my main lectures on Mondays to Wednesday's. Thursday's and Fridays I will make it as a practice and tutorial class and I could get son help from the students to coordinate small group rehearsals and practice with the ear-training and choir.
However I will be away from 21th to 30th July 2016 in which I have alerted this to Mr Sukanit. Since we already have the schedules in advance, this gives me time to plan up for rehearsals and tutorials during my absence. I already have good students in mind to help me with the tutorials. Would this work for you?