This is possibly the most popular (that is: the most played) piece in Finnish classical music. This piece became so popular that since it was first published in 1898 they took over 100 prints in Finland just during the first 50 years. No Sibelius piece ever came this close.
'Pianist' magazine published this in the scores section of their magazine and it was such a big hit that people wrote in commenting about it, asking for more Merikanto. They mix up a few rarer selections with popular ones and this one proved to be unusually popular!
Dieses wunderschöne Stück scheint wohl auch eine Inspirationsquelle für ABBA, "Thank you for the music", gewesen zu sein (einige Elemente der Melodik, Harmonik und des gesamten Charakters. Das wird besonders deutlich im Vergleich mit Klavierfassungen des Songs, z. B. mit der Sängerin Amanda Seyfried).
I thought the a might stand for accelerando in some way but it didn't take it too seriously because the rubato is written very explicitly throughout the piece anyway