This is a really nice piece of writing! You used a lot of good idiomatic language and the whole thing sounds very natural. The one correction I made is to change "all the time" to "the whole time". "All the time" is used when we talk about something always happening or happening very often. For example, "I study all the time" or "In England, it's overcast all the time". "The whole time" means the entire duration of a particular period. So you would use "the whole time" to mean "We rehearsed my test song throughout the entire duration of the period I spent at Vivian's place".