Hi Kate,
I can confirm that you have exceptional talent in music, singing and composition.
These matters have nothing to do with "Capricorn and Mars in the second house," I can assure you of that... 
What music in the chart relates to are the aspects of Mercury, Pallas and Neptune.
Mercury rules singing and the act of being a musician. Pallas rules anything that is logical and sequential, including musical composition. And Neptune, as you may know, is the overall boss of "creativity".
In general terms, the more aspects you have back to these planets by other planets in your chart, the more power, ability and larger "operational area" you have in relation to the subject.
In the geocentric longitudes, you have a large grouping of planets from 13.1 to 17.7 degrees. There's much "gold" here.
With Pallas having the highest numerical value, the grouping that involves Pallas, and therefore musical composition, also involves: Ceres, Jupiter, Mercury and Saturn.
Coming from the lowest numerical value, we get a larger grouping that is Vesta, Pluto, Juno, Saturn, Mercury, Jupiter and Ceres.
What this suggests is your composing skills (Pallas) will function differently from your singing skills (Mercury).
If we look at the basic quality of voice, you have the important planet for "power" in the synch, which is Pluto. Many famous singers have the Pluto aspect to Mercury in either their geocentric or heliocentric chart. Pluto's presence in the voice can easily be heard. We are talking Chaka Khan, Celine Dion, Grace Davies, David Byron and Gregory Porter to name a few.
You also have a very tight aspect between Mercury and Jupiter, which is great. In Magi Astrology, the combination of Jupiter and Pluto in a synch is the so-called "super success" energy, so that's available regarding singing for you. But as has been mentioned in this thread, success in music requires hard work. Lots of it.
Another interesting aspect in your geo chart is the trine between Venus and Neptune, where the Jupiter/Chiron midpoint is closely conjunct Venus. This says you can have a successful career (Jupiter/Chiron) in beautiful (Venus) creativity (Neptune). At the moment, you can think of that as a creative booster energy that's lying in wait, ready to become activated. A two-planet-and-a-midpoint aspect doesn't mean too much by itself, but the combination of Venus and Neptune holds awesome creative power that can be activated in combination with another chart. If you partner up with a person whose chart links into this positively, if you sign a contract or launch a recording that ties into this aspect.... a similar construct actually applied to Jimmy Page and the launch of the Led Zeppelin I album. In his natal chart his Jupiter/Chiron midpoint also points to "a promise" that was realised but the launch of that record in the USA on 12 January 1969.
Then if we look at the geocentric declinations, you have an important synch here also, which is Juno parallel Pallas, with both of them contra-parallel Mercury. So here we have an additional connection between singing (Mercury) and composition (Pallas) -this time mixed in with Juno.
Now swapping to the heliocentric dimension, starting with the latitudes. Here you have some fantastic creative aspects. Jupiter and Neptune are both parallel earth and this holds potential for creative (Neptune) success (Jupiter). Mercury is contra-parallel Uranus, which helps with fame (Uranus) in music (Mercury).
Then if we go into the Zodiac 7 realm (which is comprised by the 7th harmonic aspects, and which has been found to be important) we find an awesome structure that's comprised of Mercury, Venus, Pluto and Neptune. Now you have "astrological license" to have a beautiful (Venus) powerful (Pluto) and creative (Neptune) voice (Mercury). This is outstanding and it also holds a lot of financial power, as Venus, Neptune and Pluto all have bearing on finances. Good work !!
So, that's a quick look at your chart. There is one more thing I'd like to discuss, it's not technically a weakness, but more of a sub-optimal factor. It's another structure that can become a massive advantage for you.
But to summarise, you have the astrological potential for a rewarding career in singing, composition and music.
And yes, as Mercury also rules both writing and travel it's only natural these will both be interestes of yours.