Are these words concrete or abstract nouns?

Whenever I think of a concrete noun, I think of something that can be perceived by the five senses.

I was wondering, if I could see a particular practice taking place, as in a series of football drills, would the word 'practice' be a concrete noun? I can also see a 'lesson' taking place, so would that also be a concrete noun?

Also, are sounds concrete nouns too? I can hear a 'bang', so would it be classed as a concrete noun?

Thanks in advance for any answers to clarify this.