For example, if a lyric contains “that you”, it ends up like “thatchoo”. One example of this I can think of is in Karma by Taylor Swift (I know, I know, but it’s one of the most popular songs I listen to). The line where she sings “Karma’s a relaxing thought/Aren’t you envious that for you it’s not?” sounds like “arentchoo”. It doesn’t happen every time but it seems to happen unless you’re consciously making an effort to not make that sound. An example of this is in Love Story where she sings “That you were Romeo/You were throwing pebbles”, and it sounds like if you were just talking to someone and said “that” and “you” separately.
I’m just wondering if this happens in other languages with different combinations of sounds? It probably happens with other sound combinations in English too, but this is the easiest example to think of.
Something similar in German is if a verb ends with “st” followed by “du” (you), it’s squashed down to “-stu” …
from a song “Sag mal, weinst du oder ist das der Regen…” becomes “weinstu”
“hast du” …“hastu”
There are also weird German rules about article endings. A band I like has a song called “Herz Eines Trache” which means Heart of a Dragon. I don’t speak great German, so first time I heard it I wasted an embarrassing amount of time trying to figure out what eine Strache is.