sing along with的理解与搭配

目前 sing along with 几乎是一个固定搭配。请问各位老师 along 到底的意思是呢？能不能直接用 sing with the song 呢？

sing along 中的 along 意思随同一块的意思，依据《牛津短语动词词典》短语词典：后接某人时用 sing alongwith；后接某事物时用 singalong with / to。该词典对该短语的讲解为 tosing together with sb who is already singing or while a record, radio, ormusical instrument is playing 伴随（某人、唱片等）唱。如：

1. If you know the words, sing along with us. 假如你了解歌词，请跟大家一块唱。（《韦氏高阶英语词典》）

2. He sang along with the CD. 他跟着光盘唱歌。（《牛津短语动词词典》）

3. We listen to childrens shows on the radio, and Janey can sing along with all the tunes. 大家收听收音机上的六一目，珍妮能跟着唱所有些曲子。

4. We sang along to all the songs. 大家跟唱了所有些歌。（《牛津短语动词词典》）

5. You can sing along to your favourite Elvis hits. 你可以跟着一块唱你最喜欢的猫王的火爆音乐。