I have no idea, but I've learned to trust Neojaponisme on these sorts of things. So here is Matt Treyvaud's tightly curated little playlist of summer dad music for sitting on the engawa, watching the kids hunt semi. Read Treyvaud's descriptions because, again, I have no idea, but I tracked down some videos and Amazon.jp links to sample them:
the ethereal country music of Oshima Yasukatsu,
zoning, synthy 70s jazz from Fukumachi Jun,
and Taj Mahal Travellers' underground Vangelish rock.
Dad music for the Japanese summer [neojaponisme]