南武線も常磐緩行線も常磐線(郊外)も車外スピーカーでメロディ流してるけどそれぞれ名目や仕様に差があるのがな……(メトロ方式はコストなんかなぁ)
Mastodon is the best way to keep up with what's happening.
Follow anyone across the fediverse and see it all in chronological order. No algorithms, ads, or clickbait in sight.