9 January, through the years, seems to have been a propitious day for the birth of singers and musicians.
Wikipedia's details of births for this day has more musically inclined people than I usually notice. Some names are familiar, some not universally well-known. I've picked four from the many; four for whom Astrodatabank has times of birth. It could be interesting to compare the charts, because initially one might not expect a glut of musical talent to be aligned with Sun in Capricorn.
Natal charts, with data from Astrodatabank are shown later and together, for ease of comparison.
In date order:
Born 9 January in 1928, a name possibly unfamiliar to anyone not "of a certain age" : Domenico Modugno, Italian singer and songwriter of the late 1950s and 1960s who co-wrote, sang and had a huge hit with
Volare ("nel blu dipinto di blu"). His rendition of
Piove (
Ciao Ciao Bambina) is still, for me, the definitive. I shed many a tear over it back in my Italian-tinged youth. Later in life Modugno got into Italian politics, by the way.
Piove (sniffle!). It was Italy's entry in the Eurovison Song Contest, 1959.
Born 9 January 1941 ~ Joan Baez - surely familiar to all - almost iconic in fact: American folk singer , recorded over 30 albums; songwriter, musician and human rights activist, campaigner for peace.
Here she is, not a protest song this time, but with Bob Dylan's
Forever Young - still sounding great!
Born 9 January 1943: Scott Walker, American lead guitarist, singer, keyboarder and composer, member of the Walker Brothers trio. 1960s and 70s hits included
My Ship Is Coming In, The Sun Ain’t Gonna Shine Anymore, No Regrets. His songs were often filled with melancholy. Scott Walker is the most under-appreciated singer of the 20th century. He has sung straight-ahead pop, wonderful renditions of works from The Great American Song Book which compare admirably with any of the biggest name vocalists; superb versions of movie theme songs, interpretations of Jacques Brel's songs- very difficult to do I'd guess; and many self-penned songs, poetry filled with angst but showing off that creamy smooth voice, instantly recognisable as Scott Walker. Yep, after a trawl through YouTube - I'm a fan -all over again! (PS: Bingo! His Mercury and Venus conjoin my natal Sun!)
Singing his favourite Jacques Brel song
Alone 
Born 9 January 1944:
Jimmy Page, English multi-instrumentalist, songwriter, and record producer, member of The Yardbirds band from 1966 to 1968, later founded the English rock band Led Zeppelin.One of the most influential guitarists and songwriters in rock music.
Jimmy Page with Robert Plant ~
Since I've Been Loving YouTHE CHARTS
General similarities:
All four have a Capricorn Sun, of course, which indicates a certain serious, common sense attitude to things in general, including business matters - which, though not an essential part of the musical arts, has to be a help in ensuring some level of worldly success.
3 of the 4 charts have Sun/Mercury conjoined = powerful drive to communicate.
3 of the 4 have Venus (the art and music planet) in Sagittarius. Sagittarius is Jupitarian in character and expansive; we could interpret Venus in Sagittarius, then as indicating a powerful draw towards some sphere of the arts.
(Odd one out in both cases = Scott Walker, who has Venus/Mercury conjoined in Aquarius.)
Other than the above, key to
Domenico Modugno's chart, I'd say, is a limelight-loving Leo Moon and communicative Gemini rising. His later draw into politics is likely reflected in Saturn's position in Sagittarius, alongside Venus....providing a "second string to his bow".
Important in
Joan Baez' chart, are a series of wide-ish harmonious trines: Sun/Mercury trine Moon/Uranus trine Neptune forming a loose Grand Trine in Earth with a slightly Airy overtone. It's that link of rebellious Uranus to her Sun/Mercury that powers her draw towards social activism; the link to Neptune powers creativity.
For
Scott Walker, a post from my archives gives more astro information
see
http://twilightstarsong.blogspot.com/2010/11/music-monday-scott-walker-jacques-brel.html From that post
What stands out for me: Grand trine in Air signs which he shares with many of his age group (including moi). In Scott's case the generational trine between Neptune and Uranus links to personal planets Mercury and Venus in Aquarius - connecting this Airy circuit of mavericky creativity to art and communication, so it becomes extra- specially relevant in his personality and in his music.
Sun in Capricorn reflects a serious nature, though not necessarily morbid, or reclusive. To pinpoint that side of Scott's nature we go back to the Grand Trine and note that Saturn lay conjunct Uranus as he was born, and Pluto lay in opposition to Mercury/Venus. The presence of these two potential dampers (Saturn and Pluto) on an otherwise positive configuration explains Scott's early retreat from the spotlight, and his draw to darker, melancholic themes. While Saturn/Uranus conjoined explains how Scott's music can be categorised by the opposing terms "experimental" and "Baroque" (as at Wikipedia). Saturn hooked up to Uranus -the old hooked up to the new!
Watery Pisces Moon and Cancer rising underscore a deeply emotional and sensitive character, which I think can be seen from his young face, and sensed from many of his vocals.
Jimmy Page's Sagittarius Venus is opposed by Uranus and Mars in Gemini - which describes a balancing of Venus's intrinsic artistic beauty with the rebellious, avant garde Uranus and dynamic, aggressive Mars. Sagittarius Venus sextiles creative Neptune in Libra and trines Uranus/Mars in Gemini....superbly configured for a rock musician! Cancer Moon and Scorpio rising add emotional depth.
On Pasolini: "Italian actor and director of radical films, best known for controversial films about people in conflict with the mainstream society. A virtual Renaissance man who was "poet, novelist, scholar, film critic and theorist, reforming zealot and creator of large scaled visual spectaculars," he wrote and produced "Boys," and "Sebastian." Poetic and literate, a Marxist yet bourgeois in his efforts to be socially correct, he died under circumstances as perverted as those seen in some of his films. ..............His unorthodox views led to his arrest in 1962 on charges of insulting the church in his film "Rogopag." He clashed frequently with Italian authorities over the content of his films, which held liberal doses of sex, violence and blasphemy, at times being declared obscene...... His own death could have been scripted into one of his features. Pasolini was bludgeoned to death by a 17-year-old youth who claimed that he had made homosexual advances, 11/01/1975, 11:30 PM, Civitavecchia, Italy. The boy then ran him over (several times) with Pasolini's own Alfa Romeo." 
Born 9 January 1943: Scott Walker, American lead guitarist, singer, keyboarder and composer, member of the Walker Brothers trio. 1960s and 70s hits included My Ship Is Coming In, The Sun Ain’t Gonna Shine Anymore, No Regrets. His songs were often filled with melancholy. Scott Walker is the most under-appreciated singer of the 20th century. He has sung straight-ahead pop, wonderful renditions of works from The Great American Song Book which compare admirably with any of the biggest name vocalists; superb versions of movie theme songs, interpretations of Jacques Brel's songs- very difficult to do I'd guess; and many self-penned songs, poetry filled with angst but showing off that creamy smooth voice, instantly recognisable as Scott Walker. Yep, after a trawl through YouTube - I'm a fan -all over again! (PS: Bingo! His Mercury and Venus conjoin my natal Sun!)
A Yod (Finger of Fate) in Walker's chart is interesting. It links the sextile between Jupter and Sun/Mercury to Saturn in Aries via two quincunx (150*) aspects.
Although he is of the same generation as the Beatles and Rolling Stones, and was in at the start of the whole rock and roll shindig, as well as the crazy psychedelic period, he seems never to have been bitten by either bug. He remained aloof from it all, following Thoreau's famous advice: If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away. Scott Walker seemed more like a throw-back to past decades, more akin to Sinatra, Jack Jones and other crooners than to his contemporary rockers.....yet he was different, even from the standard crooners. 
As for an astrological link to Jacques Brel, it can be found in Brel's ascendant - 9 degrees Aquarius, very close to Scott's Mercury/Venus; and in their common Pisces Moon.