Although listed as an EP, Piano Man is probably closer to a
"maxi-single" in that its title track "Piano Man" is featured with two
alternate mixes (fortunately, "Piano Man" is such an accomplished song
that it totally merits these alternates). The other new track is
"Gentleman", which is structured over a repeating saxophone melody and
follows a classic 1930s jazz guitar rhythm groove. "Love Lane" is a
light electronic pop tune that was released earlier on the Marriage, Not Dating OST. 
1. "Piano Man" (title track) (Lyrics by Kim Eana (김이나), Composed by Kim Do-Hoon/eSNa, Arranged by Kim Do-Hoon, Rap by Moonbyul): This piano-driven "electronic-swing" tune is based on an uptempo 2-beat rhythm and features melodic string counterpoint in the choruses, as well as many exciting piano fills. The lyrics describe a bored person who is suddenly transfixed by the entrance and performance of a mysterious pianist.
Electric Piano: Hong So-Jin (흥소진)/Kim Do-Hoon (김도훈), Guitar: Hong Jun-Ho (홍준호)Background Vocals: Mamamoo, 박은위
0:00: Ending cadence as vocal intro (Hwasa) with piano.
0:15: Brisk 2-beat piano groove, 1st verse (Solar) with scratched brass.
0:41: 2nd verse (Hwasa).
0:57: Pre-chorus with ascending cadence (group).
1:04: Chorus (Wheein, Solar) with string accents, end cadence (Moonbyul).
1:29: 2nd verse (Wheein) with breaks and subtle guitar fills, pre-chorus.
1:53: Chorus (Wheein, Solar), end cadence (Moonbyul).
2:17: 3rd verse (Moonbyul rap), pre-chorus (Solar).
2:40: Pre-chorus with key change up (Solar/Hwasa).
2:49: Chorus (Solar) with more developed strings, ending cadence (Moonbyul).
2. "Gentleman" (with eSNa) (Lyrics by Kim Eana (김이나), Composed by Kim Do-Hoon & eSNa, Arranged by Lee Sang-Ho, Rap by Moonbyul): This casual groove (with many creative rhythm breaks) features a sampled saxophone lead line in each verse and 1930s jazz guitar comping to evoke a cinematic feeling. The addition of eSNa makes this essentially into a vocal quintet. The lyrics describe the speaker's love for a sensitive, soft-hearted gentleman.
Electric Piano: Hong So-Jin (흥소진), Guitar: Hong Jun-Ho (홍준호)
Background Vocals: Mamamoo, eSNa
0:00: Sexy sax sample intro.
0:10: 1st verse (Hwasa, eSNa) with sax lead, bridge (Hwasa).
0:38: 2nd verse (Wheein, Solar) (stop time rhythm).
0:58: Chorus (Wheein/Solar).
1:08: 3rd verse (Wheein, Solar), bridge (Solar).
1:36: 4th verse (Hwasa, eSNa), drums drop out for first half.
1:56: Chorus (Hwasa/eSNa).
2:06: 5th verse (Hwasa, eSNa), bridge (Hwasa).
2:34: 6th verse (Moonbyul rap).
2:54: Chorus (eSNa/Hwasa).
3:03: 7th verse (Hwasa, Wheein, eSNa, Solar) with stop time rhythm.
3:22: Bridge (Hwasa)/coda.
Electric Piano: Park Woo-Sang, Guitar: Lee Sung-Ryul (이성렬)
Background Vocals: Jung Geun-Young (정근영)
0:00: Electric piano and spoken male vocal intro.
0:11: 1st verse (Wheein, Solar) with electronic drums , then added acoustic guitars.
0:32: Pre-chorus with descending harmony (Wheein).
0:43: Chorus Part 1 (bass rhythm enters) (Wheein, Solar).
1:04: Chorus Part 2 (scat trio).
1:30: 2nd verse (Hwasa), Pre-chorus (Solar).
1:52: Chorus Part 1 (Wheein, Solar).
2:14: Bridge (Wheein, Solar).
2:32: Chorus Part 1 (Hwasa, Solar) (restrained in first half, then accented).
2:54: Chorus Part 2 (scat trio) with added synth line, strings.
4. "Piano Man" (Piano ver.): This version is backed by piano in the first part, but at the first pre-chorus brush drums enter, as well as some intermittent strings.
Complete Releases and exclusive online tracks
140818 "Love Lane - Moonbyul's Rap" (Fancafe)
140829 “Boy Jump” (소년점프), Baechigi (Feat. Hwa Sa)
140918 “This Song” (이 노래), Mamamoo and Loco (My Lovely Girl OST)
141121 “Piano Man” digital single (MV released the day before), Piano Man 2nd Mini-album.
141201 “Pink Panties” (Blurred Lines Cover), Hwa Sa (MV Only)
141206 “Stay” (Rihanna cover), Hwa Sa
141222 "Piano Man (Hwasa demo)" (Fancafe)
141230 “The Sunlight Hurts” (햇살이 아파), Standing Egg (Feat. Whee In)
150110 “Wait A Minute” (잠깐만) - Immortal Song 2 OST
150205 “My Everything” (내 눈 속엔 너) (SPY OST)
150214 “Flying into the Night Sky” (깊은 밤을 날아서) - Immortal Song 2 OST
150217 “Drinks Up”, Ja Mezz (Feat. Hwa Sa)
TV/Radio Songs (debut appearances)
140822 “I Heard a Rumor” - SBS Love FM
140905 “Don't Be Happy" + "All Of Me”, Mamamoo with Bumkey - Yoo Heeyeol's Sketchbook
140910 “Save Me From Myself" (Christine Aguilera) - SBS Radio
140910 “I Heard It Through A Rumor” (풍문으로 들었소) - SBS Radio
141118 "Piano Man" 1st Comeback Stage - SBS MTV The Show
141119 "Piano Man" 2nd Comeback Stage - Show Champion (better quality video)
141205 "Piano Man" with new intro - KBS2 Music Bank
141217 “A Real Lady” (Swings) - KBS Cool FM Super Junior's Kiss The Radio
141223 "Santa Claus is Coming to Town" - MBC FM4U Noon's Hope Song
141224 "Must Have Love" (Solar, Wheein) - MBC Standard FM
141227 "Piano Man (Vegas Lounge ver.)" - MBC show!
141228 "Gentleman" SAF fan meeting (cam)
141228 “One Night Only” - KBS Open Concert
141228 “Sunny/Proud Mary” Mamamoo with Insooni - KBS Open Concert
141231 “Mr Ambiguous with 80s-90s Medley” - 2014 MBC Gayo Daejejeon
150110 “Wait A Minute” (잠깐만) - Immortal Song 2
150125 "Orange Colored Sky" (Nat King Cole), Hwa Sa - KBS Cool FM K-POP Planet
150128 "Piano Man w Scat Intro" - Gaon Chart K-POP Award
150208 “Diamonds” (Rihanna), Hwa Sa - KBS Cool FM K-POP Planet
150214 “Wonderful Confession＋Flying into the Night Sky” (깊은 밤을 날아서) - Immortal Song 2
150222 “One Candle" (G.O.D. cover), Hwa Sa - KBS Cool FM K-POP Planet
150228 “Passion Flower” (정열의 꽃) - Immortal Song 2
150308 "My Dream" (Yoon Mi-rae), Hwasa - KBS Cool FM K-POP Planet
150322 "Gentleman" (Hwa Sa with Jaejin, Hyunsik) - KBS Cool FM K-POP Planet
150328 “Is You” (Whee In & Geeks) - Yoo Heeyeol's Sketchbook
Live Concert Songs
During this era, MAMAMOO included 8 songs in their live repertoire: "Mr Ambiguous" (also remix & with 80/90s Medley), "Piano Man", "Peppermint Chocolate", "Love Me", "Baton Touch", "Love Lane", "I Heard It Through A Rumor", "Don't Be Happy"
Also: Early in 2015 RBA and WA merged to form RBW (Rainbow Bridge World).
