1) (of a tune etc) easily remembered (catchy)

2) a metallic ringing sound (as of coils, keys or small bells); a short and simple phrase or poem, especially with a simple tune, that is easily remembered (jingle)

3) deserving to be remembered because special (memorable)

4) remembered experiences (spoken or written) (reminiscences)

5) an easily remembered phrase used to advertise something or to make clear the aim(s) of a group, campaign etc (slogan)