In this forex chart, the British pound is a major, while the Singapore Dollar is not. Since neither of the two currencies are commodity currencies and because direct trading between them is not significant volume-wise, the pair itself is neither a commodity pair, nor a major.
The British Pound is not only the world’s oldest currency still in use today, it is also the highest valued major. Though over the last few years, it has been hit with more pronounced inflation, it is still worth more than the USD, the EUR and even the CHF.
The GBP is backed by a powerhouse economy covering energy, agriculture, services, manufacturing and finances. The main trading partners of the UK are some of the biggest and strongest economies of the world: the US, Germany and France.
With the 2016 Brexit vote, it has become obvious that the GBP would never be replaced by the EUR.
In regards to the Singapore Dollar, it has to be noted that it is a relatively young currency. The country itself only became independent from Malaysia in 1965, which is when the SGD was introduced.
The authority in control of the SGD is the MAS (the Monetary Authority of Singapore), and it has done an outstanding job of keeping the currency stable, by pegging it to a basket of currencies.
Indeed, the value of the SGD in relation to the USD has been rising steadily since 1981.
The geographical distance between the two countries means that the UK and Singapore occupy rather disparate economic spheres. While Singapore is small, it wields surprisingly strong economic influence. The cornerstones of Singapore’s economy are services and the finance industry. The GBP/SGD pair may be useful for carry trading, on account of the stability of the SGD.