Trashy lyrics. Take out the 着 changes the meaning.
只要看著你 Once I see you / Whenever I see you
只要看你 I just want to see you
There is no sense of continuous action, rather, repetitive occurrence, he is saying, 'Any (and every) time I see you, I remember the time we met.'
LuHan:停不住 我鼓足勇气去爱 can't stop I('ve got to) keep up the courage to love
Lay:只要看著你 just need to look at you
Lay:画面 倒回被命运击中的一刻 (and I) picture the moment destiny brought us together
我听见一个梦从银河降落 I heard a dream descend from the milky way
着 is used a lot in Chinese, but I find it mostly does not correspond to what is called 'the continuous aspect' in Western grammar, although it may in certain situations. So you should not just think, 'Aha, 着 = -ing.'
(Cf: 小王的眼睛闭着，Xiao Wang’s eyes were closed, (not 'closing') If 'closed' is 'continuous aspect' what is Past Tense?)
This sentence talks about a big old bird, which 'lived', not 'is living', a long time ago. In English, the so-called Present Tense mostly fulfills the task of indicating continuous action: I live in South America.