Rod Wave’s new album “SoulFly” extracts maximum melancholy, while Lil Tjay’s “Destined 2 Win” can’t find a firm grip.“Tombstone,” from the excellent new Rod Wave album “SoulFly,” is a startling soul hymn about unshoulderable weight. Wave, 21, is a tender singer deploying the cadences of a rapper, and on this song he finds a way to sing — about the burdens of fame and how they are simply high-priced replacements for the burdens that came before fame — with gospel-like invigoration and blues contemplation.Last week, just after “SoulFly,” Wave’s third album, debuted atop the Billboard album chart, Wave performed “Tombstone” on “The Tonight Show Starring Jimmy Fallon.” Singing on a riverside porch, Wave gave off an air both baptismal and funereal:I keep my gun in my draws, ducking the sad newsMy phone say seven missed calls, I know it’s bad newsThis life had left me so scarred, I’m knowing that’s trueRemember times got so hard, I got it tattooedOne week after the release of “SoulFly” came the second album from the 19-year-old Lil Tjay, “Destined 2 Win,” which just debuted at No. 5. If Wave is the bluesman of this generation of sing-rappers, Tjay is the sweet crooner. Both traverse the same subject matter — more money, more problems; untrustworthy partners and the loyal ones who make up for it; skepticism about just how steady their perches are. But where Wave extracts maximum melancholy from these themes, Tjay’s approach is thinner and more brittle, rarely landing hard on a solid feeling.Wave is perhaps the pre-eminent hip-hop emoter of the last couple of years, and he chooses templates that allow his voice to ooze freely: guitar-led arrangements that recall schlocky 1980s radio rock, or elemental drum patterns. Many of the songs are short — a couple of choruses and a verse, sometimes just the verse. And Wave has a particular way of handling some of his line-ending syllables, breaking them into three descending steps, as if giving himself over to gravity.Mostly, he leans in to lamentation, like on “Gone Till November” and “How the Game Go,” plangent takes on overcoming adversity. On “Don’t Forget,” in between snippets of an old aggrieved Pimp C interview, Wave displays at least a brief glimmer of boast: “Rod crashed the ’Vette, but he came back in a better one/‘Rod fixed the ’Vette?’ Nah dog, this here the second one.”On paper, Tjay is working similar emotional territory. “I just rap about my pain ’cause I know others could relate,” he insists on “Slow Down.” And dating back to his earliest singles, like “Brothers,” Tjay has taken a microscope to the conditions that raised him. On “Nuf Said,” he nails a particular kind of intractable sadness relating a friend’s predicament: “Broski on the phone, he just want another chance to live/But he on his own so long in the cell, he say ‘the crib.’”Tjay’s voice is high-pitched — he’s one of a handful of current saccharine sing-rappers, including Lil Mosey — and his approach is melodic but not particularly soothing. His delivery can feel staccato, and so can his lyrics, which on songs like “Part of the Plan” tend toward the non sequitur, rhyming syllables tacked onto jumbled thoughts.On “Headshot,” the most recent single from this album, he follows his two guests, Polo G and Fivio Foreign, both of whom land harder than he does. In that way, it recalls “Mood Swings,” Tjay’s collaboration with Pop Smoke from last year, which was a hit on TikTok, largely as the soundtrack for comedic sketches about inappropriate older family members.They start with a starry-eyed kid sweetly lip syncing to Tjay about the object of their affection: “Shawty a little baddie, she my lil’ boo thang.” Then an older figure echoes them, lip syncing to Pop Smoke: “And shawty got the fatty.” The younger person agrees, lip syncing as Tjay concurs, “Shawty got the fatty,” before breaking character and staring at the flirtatious intruder, aghast.The interaction in these skits, and in the song, is almost primal — Pop Smoke, the gruff alpha, out to tame Tjay, and possibly walk off with his woman. It’s about power, but also authority. While those around him are staking hard claims to emotions and everything else, Tjay is still casting about, looking for a firm grip.Rod Wave“SoulFly”(Alamo)Lil Tjay“Destined 2 Win”(Columbia) More