Spring is definitely a time for indie, alternative, can't-quite-pigeon-hole songs. Grouplove's Shark Attack, Class Actress's Keep You, Sufjan Steven's I Walked, Fitz and the Tantrum's Fools Gold, Kwabs's Walk... practically anything breezy with some backbone. Grace VanderWaal is great, too.
Summer is Kings of Leon, My Chemical Romance, Panic! At the Disco, Red Hot Chilli Peppers, Icona Pop, Sia and some Lana Del Rey for when you start to get a headache. Sigrid is always good at this time of year, too, and Alex Lahey.
Autumn is Metric, hands down. Some nostalgia pieces, too - things that wake up the kid in you who remembers the red leaves on the pavement. Santigold, Muse, 4 Non Blondes, The Verve's Bittersweet Symphony, The Temper Trap, Of Monsters and Men and U2.
Boz Scaggs with his jazz endeavours are a Winter deal. 80's is usually good at this time of year... and some Rihanna, Tove Lo... it's such a boring time of year. The usual playlist is worn out, so this is when experimentation goes on. Try and get familiar with the latest and greatest hits, which are usually terrible because most people have no discernment. But Imagine Dragons and Years & Years are good sources of comfort.