The common word “something” can have several soundshapes. The last consonant may change from [ŋ] as in “thing” to [n], as in “thin.”
In very quick speech several sounds may be lost, and “something else” may sound like this:
something else
[sʌ̃ʔm̩ɛls]
[sʌ̃ʔm̩ɛls]
You may hear this when someone offers you something to drink:
Do you want milk or something else?
[dǯǝwǝnmɪlkɹsʌ̃ʔm̩ǝls]
[dǯǝwǝnmɪlkɹsʌ̃ʔm̩ǝls]
Notice also how “do you want” can sound like [dǯǝwʌn] or [dǯǝwʌ̃ʔ].
Sometimes you’ll see the spelling “sumpin”” as an attempt to represent this soundshape, as Lagunitas Brewery’s “Sumpin’ Easy Ale” and “A Little Sumpin’ Sumpin’.” These beer reviewers all pronounce “sumpin'” with the soundshape [sʌ̃ʔm̩]: