This is the 36th most frequent Chinese word.
让
"让" means "to let," "to allow," or "to make (someone do something)."
In this sentence, '让我' means 'makes me' or 'causes me to' and expresses causation, indicating that the song causes the speaker to recall the past.
这首歌让我想起了过去。
This song reminds me of the past.
In this sentence, '让他' means 'let him' and is used to politely request allowing someone to do something, in this case, to speak first.
请让他先发言。
Please let him speak first.
Here, '让你' means 'let you' or 'allow you to', denoting permission or enabling someone to perform an action.