Most of the time when a discussion of old school K-pop comes up, the same groups and songs usually receive most of the attention and with good reason. Popular songs are popular because they were able to strike a chord with fans and for many, helped to define a time in their lives. But in between those big hits, there are always a few songs that were really good, but often get overlooked. Here's a look at 10 old school songs that we all liked but maybe forgot were on our playlists.

"Official Farewell", R.ef, 1995

One of the true old school groups, R.ef (Rave Effect later becoming Ruff Eazy Flava) debuted in 1995 during the beginning of the K-pop renaissance. Members Park Chul Woo, Sung Dae Hyun, and Lee Sung Wook mixed pop with some dance beats for their self-titled debut album, and the group became stars on their first try. "Official Farewell" became a number 1 song for three weeks but is often overlooked because 1995 happened to feature some of the greatest songs in K-pop history (think Seotaiji and Boys, DJ DOC, Park Mi Kyung, and more). Even with the stiff competition, R.ef is still one of the great old school groups, and their first album also had another huge hit "Heartbreak", which is often considered their most popular song. R.ef recently announced that two of the members were preparing a comeback. Here's hoping they can relive the magic one more time.

"Snail", Panic, 1996

Panic is one of those groups that people know but don't always consider when thinking of the most popular K-pop groups. Members Lee Juk and Kim Jin Pyo brought a musicality to K-pop that was refreshing and created some of the best yet underrated songs. "Snail" was a melodic ballad that featured Lee Juk's know-it-as-soon-as-you-hear-it voice and his legendary song writing skills. This song was the duo's first big hit and has been covered a number of times through the years. Lee Juk went on to have very successful solo career and was also a part of the project group Carnival with Kim Dong Ryul. Many current fans might know him from his 'Infinity Challenge' partnership with Yoo Jae Suk when the pair performed "Apgujeong Player". Kim Jin Pyo also had a successful solo career as a rapper and just recently teamed with fellow 1977 friends Psy and LeeSsang on Psy's sixth album.

"Forever", Ahn Jae Wook, 1997

Ahn Jae Wook debuted as an actor in the early 90's and was in some popular dramas, but it was the 1997 super duper mega-hit 'Star in My Heart' that made him a superstar. On a side note, the drama also starred Cha In Pyo and the late Choi Jin Shil to become the standard bearer of all modern love triangle dramas. It'll be tough but if you can find it, watch it. In the drama, Ahn played up and coming singer Kang Min and "Forever" was the song that his character sang within the drama. Ahn rode that wave of popularity to record his first album with "Forever" as the single and notched this number 1 hit. The song is a dramatic ballad that made Ahn Jae Wook a singing sensation in real life and is one of the songs that I'll listen to from time to time when feeling nostalgic.

"The Day After You Left", Lee Hyun Woo, 1998

Lee Hyun Woo's voice has this sad, dramatic quality to it and it perfectly fit the title song of his fourth album. "The Day After You Left" is the lament of a man who just lost his love and is asking if she even loved him to being with. The song was a number 1 hit during the early part of 1998 and was probably his biggest hit to date. Lee Hyun Woo has since focused his time on acting but made a recent comeback to the music world through popular show, 'I Am a Singer'.

"Go Away", Park Ji Yoon, 1999

People often forget that Park Ji Yoon was a popular singer before she joined JYP Entertainment, and this song is a perfect example. Although it was right before working with JYP, Park reached number 1 with this hit song from her third album. Her concept in general was more on the innocent side but she was still receiving much attention for her unique voice and stunning looks. "Go Away" featured more of a techno dance sound and is another one of those songs that gets buried on the playlist, but I always enjoy it when I do get a chance to listen to it.

"Love", Jo Jang Hyuk, 2000

Both the song and the artist are hidden gems, and the song is one of the most elegant Korean ballads that I can remember. It's a simple, touching song of a man professing his love for the one he loves. I actually hadn't listened to the song until about a year after it was released when a friend of mine played it in his car as he was trying to impress a girl by singing along (that was an awkward ride), and I immediately went back to my dorm and downloaded it and had it on repeat for about three days. What can I say; I'm a sucker for ballads. The song has been remade from time to time with my personal favorite version being Ock Ju Hyun's on 'I Am a Singer'. Sorry Kim Hyun Joong fans.

"Undefeatable", Click-B, 2001

Ok, I'm not going to lie; I know next to nothing about Click-B other than they were from the same company as Fin.K.L and Sechskies. I do, however, remember this song because at the time, none of the boy bands were really using rock as their foundational sound, and so this song stuck out. Plus, it had a catchy hook that I still remember to this day. It's another hit song that sometimes gets lost in the mix, but one that takes me back to my college days and getting ready for summer break.

"Please", Wax, 2002

Wax (Cho Haeri) is one of those singers that is up there as one of the most underrated and unknown singers in K-pop, yet nearly everyone has heard one of her songs. Of her many hits, it's the title song of her third album that is my favorite. The song is a woman's request, asking her former lover's new girlfriend to take of her man by listing the things that he does and doesn't like; very reminiscent of the famous scene from the movie 'My Sassy Girl'. Wax has now focused her attention on acting and actually starred in a musical based on one of her famous songs, "Redoing My Makeup".

"Grasshopper", Lexy, 2003

Lexy was one of the best female R&B singers in K-pop, as she made her debut under YG Entertainment. This song was both her first single and her break out success that put her on the K-pop map. Featuring future YGer Psy, the song is a very catchy hip hop, R&B track that showcases her husky voice and the type of music that YG used to produce. After a few more albums, Lexy ended up transferring to another company but it was this song that many fans remember, even if they need a little prodding to jog their memory.

"We Used to Be in Love", Lyn, 2004

Before she was the older sister in love with the idol boy band members on the variety show 'Immortal Songs 2', Lyn was quite the talented singer and this hit song from her second album 'Can U See the Bright' was one of her most well received songs reaching number 1 in 2004. I couldn't name you another hit song by Lyn, but this song is many would recognize right away. It's just not always the one you listen to all the time.