Justin Bieber's Music Monday series is still in effect after he dropped 'Heartbreaker' last week. This week he croons over the minor chords of a guitar on 'All That Matters.'

'All That Matters' follows the intimacy of its predecessor, switching out the twangy pop for a more straightforward R&B feel. This second installment is noticeably sparse on the instrumental and features a more serious Bieber, who was recently seen accompanying Floyd Mayweather on his way to the ring.

"You think I'm biased too much I'll never get another / You hit it right on the head only been missing my lover," Bieber sings, as if he's specifically constructing this song to elicit tears from his adoring female fans.

Bieber could possibly keep up this intimate tone throughout the rest of the Music Monday series, which is an odd day to already be in your feelings to begin with. He plans to release 10 tracks over the next two-and-a-half months as part of the series.

Listen to Justin Bieber's 'All That Matters'