Is it polyphonic with multiple lines, or is it a pure note with just a single line?

多线复，单线纯音？

Songs with 60 to 80 beats per minute but no lyrics have been shown to reduce stress.

每分钟60到80拍的纯音乐，可以减轻压力。

Well, it seems songs no longer have an 'intro' – the instrumental piece of music that's played before the singing begins.

好吧，似乎歌曲不再有" 序曲" ——在歌声开始之前演的纯音乐部分。

While some of us prefer complete silence, an uplifting piece of non-distracting music (without lyrics) may improve mood and increase the chances of information retention.

虽然我们有些同学更喜欢安静的环境，一段振奋人心的纯音乐（没有歌词）可以改善，深知识的记忆。

Songs with 60 to 80 beats per minute but no lyrics have been shown to reduce stress even in patients who have undergone various types of surgeries.

每分钟60到80拍的纯音乐可以减轻压力，甚至在经历了各种手术的病人身上也有同样的效果。

Like R definitely changes the AW as in law vowel, it's not going to be a pure sound when R follows it in the same syllable.

就像 R 肯定会像法律元音一样改变 AW，当 R 在同一个音节中跟随它时，它不会纯音。