Yes, you can sing B-A-C-H, if ..., yes if you are living in the German-speaking language area. If you are living in the USA, Great Britain or elsewhere on the planet that is not true for you, guys. Why it's not possible in the English-speaking language area, is what you better ask your music teacher, he is even better in explaining. But I am working on providing a high quality answer in high end English here. That will come during fall 2015.
By the way, Bach probably is the only name, that you can sing, at least the only name of a musician and the most prominent, if it is about music.