Learn French: Le chant s'entend de loin. - The chant can be heard from afar.

Literally, yes! But this is called the pronominal passive. In French, when an inanimate object (like le chant) is the subject of a reflexive verb, it often carries a passive meaning. Instead of saying the song hears itself, it means the song 'is heard'.

The English translation says 'can be heard', but there is no verb for 'can' (pouvoir) in the French sentence. Why?

The pronominal passive often implies possibility or a general characteristic. While s'entend strictly means 'is heard', translating it as 'can be heard' usually sounds much more natural in English when describing what something is capable of doing or what generally happens to it.

Why do we use de in de loin instead of depuis?

De loin is a standard set phrase meaning 'from afar' or 'from a distance'. The preposition de (from) is used here to indicate the origin point of the sound or the spatial relationship. Depuis usually emphasizes a specific starting point of an ongoing action, whereas de loin is a fixed spatial expression.

Does le chant only mean 'chant', or can it mean 'song'?

It can mean both! Le chant refers to singing in general, a chant, or even a bird's song (le chant des oiseaux). However, if you are talking about a specific musical track with lyrics, like a pop song on the radio, you would usually use la chanson instead.