How to master English sounds

In this essay, I will tell you how I practiced mastering English sounds while I was trying to sing English rock songs with/in karaoke. Japanese is an intonation based language while English is a stress based language. Therefore, I needed to know proper stresses in English and how consonants and vowels connect in English, because if I didn't do these and if I pronounced English with a Japanese accent, it wouldn't fit with/into the melodies. In order to master these, I repeatedly listened to the part of the song which I could not sing properly. And I realized how sounds connected in English. For example, "when I" is pronounced like "whenai." "Can I" is pronounced like "canai." I think it was good training to master exact sounds of/in English through listening to native speakers talking and singing.