In the song Trench Town Rock, the late reggae star Bob Marley sings that "One good thing about music, when it hits you, you feel no pain." It's a sentiment we all can relate to at the end of a shift when head, feet and emotions are weary.

Music can be powerfully soothing -- an idea reinforced by a British neuroscientist's current studies of music's positive impact on brain functions. Based on Dr. Jack Lewis' findings, we  selected the seven songs at the end of this article to help us all rev up good feelings.

Brain Research Identifies Mood BoostersIn a January 2013 interview with Britain's Daily Mail,  Dr. Lewis says songs that lift mood are ones that stimulate areas of the brain in charge of emotions and feelings of pleasure.

According to Dr. Lewis, whether you're listening to favorite blues, pop rock or other tunes, feel-good music shares characteristics, such as:

• A simple style that is "punchy yet predictable"

• Harmonization of voices, as in acappella

• High-pitched, upper-register riffs

• Simple melody along with a fast pace and

• Composition in major versus minor keys.

Songs that lift mood, Dr. Lewis says, also include ones connected to happy times in our lives. For example, playing a ukulele stirs good memories for billionaire investment specialist and philanthropist Warren Buffett of Berkshire Hathaway. A 2008 NPR interview and recording notes that Buffett strummed a ukulele when courting his wife.

Ukuleles Raise SpiritsFor anyone who grew up in the 1960s, the tiny, guitar-like ukulele may conjure talent-show hula dances. Yet its resurgence in recent years has led to some of the lightest, brightest hits on pop stations.

According to Florida's Sun Sentinel, during the economic hard times of recent years, ukulele clubs became popular due to what fans perceive as a "happy sound." Consequently, two of the songs in our "unwind" list feature the cheerful strains of the ukulele.

Seven Songs for UnwindingBrave. Sarah Bareilles' lyrics and forceful delivery encourage listeners to be brave about speaking up. "Say what you what you wanna say / And let the words fall out," she urges to a catchy beat.

Barbara Ann. The rhythm, harmony and fast-paced lyrics of this Beach Boy's favorite can get you "rockin' and a rollin'" when you're "rockin' and a reelin'."

Count on Me. Bruno Mars recorded and co-wrote this song about being a good friend in times of need. High-pitched, twangy ukulele adds charm to bouncy lyrics, such as "You can count on me like 1, 2, 3 / I'll be there."

Happy. Pharrell Williams used catchy repetition in this airy song about a happy attitude so powerful that "Can't nothing bring me down."

Home. Here's another positive song about helping a friend. Phillip Phillips' soulful rendition made songwriter Drew Pearson's words famous: "Just know you're not alone / Cause I'm gonna make this place your home."

Respect. Aretha Franklin's anthem stressing mutual respect in relationships makes you want to get up and dance or at least drum "R-E-S-P-E-C-T" to the beat on your steering wheel.

Somewhere Over the Rainbow. The movie Shallow Hal helped make Joshua Li'l Boy Shintani's ukulele version of this classic famous.

Pick the right tunes, and music will pick you up.