Do both Regina Spektor and Sons of Day specialize in similar types of music?
no
Title: What We Saw from the Cheap Seats
Passage: What We Saw from the Cheap Seats is the sixth studio album by American alternative singer-songwriter Regina Spektor.  On November 21, 2011, Spektor posted on her Facebook page that the album had been recorded with Mike Elizondo in Los Angeles during the summer of 2011.  It was released on May 29, 2012.  The album is a collection of new material along with the very first studio recordings of several of Spektor's older live songs.
Title: Regina Spektor
Passage: Regina Ilyinichna Spektor ( , Russian: Реги́нa Ильи́нична Спе́ктор , ] ; born February 18, 1980) is a Russian-born American singer-songwriter and pianist.  She was born in Moscow (former Soviet Union, now Russia), and began classical training on the piano at the age of six.  When she was nine years old, her family emigrated from the Soviet Union to the United States, where she continued her classical training into her teenage years; she began to write original songs shortly thereafter.
Title: Sons of Day
Passage: Sons of Day, stylized as SONSOFDAY, is an American, alternative rock band based out of Portland, Oregon, consisting of three brothers: Vladimir (lead vocals), Roman (guitar), and Scott Belonozhko (bass).
Regina Spektor Sons of Day